Moisture-Proofing the Griso Digitek Dashboard merged threadfest (w/ new Part 4)

[Moto]

Moisture-Proofing the Griso Digitek Dashboard
by Moto

This is the first of a set of three (now four) posts that were intended to be parts of a coherent discussion of moisture-proofing from both theoretical and applied points of view. I probably should have posted all three as a single document. Since they've now been folded into a thread with the resulting discussion, I have put links to each of the other parts at their ends for convenient access.

The three parts are:

     1. Theory and Dashboard Design
     2. Adding  a Desiccating Breather 
     3. Applying a Conformal Coating
     4. Roy-Type Breather


Part 1. Theory and Dashboard Design

Griso dashboards have a poor reputation for reliability and cost over $500 to replace. This has gotten many of us interested in how to prevent failures. Since I haven't been convinced we have attained an understanding of how to do this, I decided to take a fresh look. I'll report my findings and two practical preventative treatments here, hoping this will be of interest and/or benefit to others. I'll start with discussing principles and theories of dash failure, and the particular construction of the Griso dashboard. Followup posts will cover the two preventative treatments I have implemented, one involving complete disassembly of the dash and the other leaving it intact.

Possible causes of failures

I tried to understand what the cause(s) of the Griso dash failures might be in theory, the main possibilities being vibration, external wiring failures, and moisture.
 
Examining the dashboard (see photos below) and its flexible mounting, I quickly discounted vibration as a likely cause of failures. Besides its apparent high-quality build, I considered the background of the builder, Digitek SpA. Digitek was founded in 1983 in Modena, Italy, to provide onboard electronics (including telemetry) for Formula 1 cars. It subsequently expanded to supply dashboards for Ferrari, Lamborghini, etc., as well as mainly Italian motorcycle makers. I decided that if this firm didn't know how to deal with vibration, nobody would. (Digitek was acquired by Italian electrical equipment maker MTA Group in 2008, and still exists as an arm of what must be its later descendant, Microtec, also based in Italy. There have been some statements on the web that the Digitek that manufactured the Griso dash is the Australian electronics manufacturer of that name, but this seems to be wrong; I see the Italian firm's pre-acquisition logo imprinted on the dash circuit board, and this logo does not appear on the Australian company's websites that I have found; nor do any claims of constructing our dash.)

I don't discount the likelihood that external wiring problems account for some incorrect diagnoses of dash failure, but I decided only to pursue the moisture angle, since it seems pretty well attested, and because I felt I could make more of a contribution there. That being said, it is very important to investigate grounds and electrical connections outside the dash when a problem arises. My goal is to keep some actual dash failures from occurring.

Effects of Liquid Water

The big difference between the Griso dash and that old Marantz amplifier in your basement that's been running perfectly for 40 years is its operating environment. Being exposed to temperature swings, and also open to entry of moisture, the conditions in the dash often produce condensation, which occurs when the air inside drops to the dew point temperature. Condensation can affect the electronics -- on a printed circuit board (PCB) in this case -- in more than one way.



As water vapor condenses, it forms droplets that can bridge circuits on the board. The condensate is pure, distilled water, which is a very poor conductor of electricity. But water on a PCB immediately begins to dissolve components, like glues, used in constructing the board, forming ions that increase its conductivity, making an electrolytic solution. If enough current goes through a droplet between circuit traces or terminals, the temporary short circuit can disable the board until the droplet has the chance to evaporate away. Worse, it is possible that the short circuit is serious enough to permanently damage the board, meaning the problem will not go away after evaporation.

Another possible outcome is the formation of dendrites -- metallic, crystalline, fern-like growths that are deposited molecule-by-molecule on the board between charged conductors. As they grow, dendrites make temporary short circuits increasingly likely when condensation forms, since the distance between the circuits to be bridged decreases. Ultimately, assuming the PCB continues to function long enough, the circuits will be physically connected by the metallic bridge of the dendrite, causing a permanent malfunction. Here is a photo of such a short-circuiting dendrite on a PCB (source: www.multisorb.com/files/9113/4315/2180/article-moisture-in-electronics.pdf).


 
The Griso Digitek dash is particularly vulnerable to short circuiting of all types because of the very small pitch of the layout: the conductors are very close to each other. (The small pitch was remarked upon by a web guru called Techrat1, who will be introduced more thoroughly later.) The small pitch means greater amperage short circuits through the electrolyte can occur at lower voltages, and that dendrites have shorter distances to bridge.

Layout of the Griso PCB

Here are photos of the upper and lower surfaces of the PCB in my dash.





Most of the interesting stuff is in the lower photo. The white circle (3) is the tachometer needle stepper motor. Above it is the pin connector (4) to the Griso wiring circuits. The large gray rectangle toward the lower left (2) is the Fujitsu CPU. At the left edge of the board is the ribbon connector terminal (1) for the LCD display. To its right, the small rectangle (5) is the serial EEPROM, a memory unit that holds the parameters we set on the dash and also stores the odometer mileage record. At about the four o'clock heading from the stepper motor, right on the edge of the board, is an array of ten unused connector terminals (not numbered). These are a programming interface to the CPU.

I didn't figure all this out on my own. The information comes from an exploration of the Aprilia SR50 scooter's dashboard, done by user Techrat1 on www.apriliaforum.co m. (Here is the thread: http://www.apriliaforum.com/forums/showthread.php?180601-Digi-Dash-modding-or-repair/.) That dashboard is a simpler version of the Griso's, lacking the CAN bus, and also the air pressure sensor that will be an important part of my tale, visible as a twelve-sided shape just below and to the right of the stepper motor (6, above). Here is a photo lifted from his thread, showing the similarity to our dash:



Techrat1 was originally responding to a request about changing the color of the LCD display, but became more deeply interested in the dashboard. Aside from identifying components, he hooked up a terminal to the ten-pin connector and considered reprogramming the dash for various functions, including a Game Boy-like interface. (I think the CPU might be shared with the Game Boy, but didn't find out; the model number of the CPU seems to be different from ours, judging by the fuzzy lettering in the photo.) He found that the odometer reading in the external EEPROM could be read, and could be reset to zero but not to another value, because of a check sum that he could not crack. Along the way he demonstrated a deep understanding of what he was looking at, and made several comments useful to me, including the one about the very small pitch of the PCB, which is related to the condensation threat. (He was not concerned about condensation.) Hats off to you, Techrat1! (Let me know if you object to my pirating your photo.)

Sealing Against Water Vapor Entry

Though all of the damage will be done by contaminated, liquid water, the root of all this evil is water vapor -- disassociated H2O molecules forming a gaseous component of air. Water vapor is every bit a gas, as much as the oxygen (O2) and nitrogen (N2) components of air, and completely distinct from fogs or mists made up of fine droplets. Its molecules (H2O) are smaller than the oxygen and nitrogen molecules (about 2.3 angstroms). Once it is inside the dash enclosure it is free to condense into harmful droplets when the dew point temperature is reached.

At first I supposed the answer to the dash's condensation problem would be to seal it hermetically -- against all entry of gasses. But there are two things preventing this.

First, water vapor freely penetrates, or permeates, most if not all plastics. The molecules are small enough to travel between the polymer strands making up plastics, and the result is the equalization of the partial pressure of the water vapor inside and outside the enclosure. (They boldly go where O2 and N2 cannot.) This takes time to occur, but the result is that the water vapor in the enclosure reflects a long-run average of the environmental conditions. Even if the environment is only moderately humid, the water vapor in the enclosure will condense when the temperature drops far enough. Because of this problem, tables of Water Vapor Transmission Rate (WVTR) values are published. With the data in them engineers can model the permeation of vapor during the expected lifetime of an electronic component.

But there is a bigger problem that means the dash should not be hermetically sealed, even if it were practical. As mentioned before, mounted directly on the PCB is an air pressure sensor that is used to adjust the fuel/air mixture. This sensor is about 1/4 inch across, as seen in the two close-up photos below, before and after I removed the plastic cap that covers the transparent sensing membrane visible at the right. Successfully sealing this sensor from the atmosphere as part of a moisture-protection scheme would cripple the engine.


   

The Dashboard Vents

The dashboard has two small vents at the back of its lower surface, looking like two posts protruding about a quarter of inch:



As can be seen, the two vents are provided with baffles looking like half moons. Because no light is visible through them, they have often been mistaken for casting channels (I suppose) and ignored. (Blowing through them confirms they are vents.) Some have overlooked their presence at first, and thought they were added later in the production runs, but they are present in the drawings of the dash in the original workshop documentation. (And they are also there on the SR50's dash.) The Griso dash's vents should never be sealed up, because of the PCB's air pressure sensor.

What's Next?

In the final two posts of this set I will describe two methods of combatting the moisture problem. The first, non-invasive procedure adds an external desiccating breather to admit air from which water has (largely) been removed. The second, quite invasive approach is to disassemble the dash completely and treat it with a "conformal coating" that controls the approach of water vapor molecules to the PCB. I'll post pictures of what's involved.

I've read quite a bit about this stuff, and want to avoid going on at too much length. I can provide references to some sources I recorded, all from the internet, but including corporate product pitches, university-posted material for students, and scientific/technical reports in addition to forum exchanges of dubious provenance, such as this one.

Skip to:
Part 2. Adding  a Desiccating Breather 
Part 3. Applying a Conformal Coating
Part 4. Roy-Type Breather

[Dean Rose]

You need to get WO in on this.

Dean

[jlburgess]

The last time I had mine apart I put a small packet of moisture absorbing dessicant inside of it.  Not sure if that helped  but it has lasted much longer than the first two units.  It still fogs up occasionally even though I never let it get wet.  The fogging usually occurs when the face is exposed to direct sunlight, especially when parked.

[Moto]

The last time I had mine apart I put a small packet of moisture absorbing dessicant inside of it.  Not sure if that helped  but it has lasted much longer than the first two units.  It still fogs up occasionally even though I never let it get wet.  The fogging usually occurs when the face is exposed to direct sunlight, especially when parked.

That's a good approach, but where the heck did you put it? (Griso, right?) Under the clear gauge cover? In the little recess around the stepper motor? The clearance between  the plastic case and the bottom of the PCB is almost nil. I gave up on that idea for lack of room, maybe too soon.

[swooshdave]

GMs Optispark used a vacuum to pull ozone and moisture from the ignition system. Would it be possible to hook up a vacuum line from the intake for a mild suction?

[jlburgess]

That's a good approach, but where the heck did you put it? (Griso, right?) Under the clear gauge cover? In the little recess around the stepper motor? The clearance between  the plastic case and the bottom of the PCB is almost nil. I gave up on that idea for lack of room, maybe too soon.

I put it in behind the rear cover where the wires go in.  It was a small packet, about 1 inch long and 1/2" wide.

[not-fishing]

I choose not to ride in the rain, garage my Griso and today it's supposed to be 101, tomorrow 106 with 16-20% humidity.

[Moto]

GMs Optispark used a vacuum to pull ozone and moisture from the ignition system. Would it be possible to hook up a vacuum line from the intake for a mild suction?

[EDITED after I finally understood what you meant.]

Yes. There is a provision in the castings that could be adapted for that. I never thought of using intake vacuum for that purpose. Thanks for the idea!

My non-invasive setup uses both vacuum and positive pressure for purging. Details to come.

[Moto]

You need to get WO in on this.

Dean

I'd like that. But where is he? (PM me if his identity is secret.)

[ohiorider]

Informative document.  I'd love to find whatever disabled my LCD on my 1200 Sport dash.  Carmo wasn't able to repair it.  Everything on the dash works except for the LCD.  I'm currently running a used Breva 1100 dashboard, which displays most all the indicators .... a couple of warning lamps don't light, but everything else is functional, and front and rear turn signals also function.  Can also access diagnostics.

If Carmo (repair facility) could have sourced an LCD panel, I believe they could have repaired my dash.

Bob

[Moto]

Informative document.  I'd love to find whatever disabled my LCD on my 1200 Sport dash.  Carmo wasn't able to repair it.  Everything on the dash works except for the LCD.  I'm currently running a used Breva 1100 dashboard, which displays most all the indicators .... a couple of warning lamps don't light, but everything else is functional, and front and rear turn signals also function.  Can also access diagnostics.

If Carmo (repair facility) could have sourced an LCD panel, I believe they could have repaired my dash.

Bob

You might take a look at Techrat1's comments, cited above. The backlight for the LCD has its own power, supplied I think via the two copper-plated fiberglass connectors he describes. The information on the LCD gets transmitted separately via the ribbon cable, the connector on the left side of my photo. After entertaining a plea from a forum member for more ideas about modding the LCD, Techrat1 said, "The LCD is very hard to remove from the frame... I would not recommend doing it for any reason...." It's important to note that, unlike me, Techrat1 was dissecting a dead dash, with no intent to restore it to service. (My dash still survives.)

John/Moto

[rtbickel]

Could you connect tubes to the ventilation ports and run them to a container filled with a dessicant material so that it could only breathe through the dessicant?  Using cannisterectomy parts would please the red suspenders crew. 

[Moto]

Could you connect tubes to the ventilation ports and run them to a container filled with a dessicant material so that it could only breathe through the dessicant?  Using cannisterectomy parts would please the red suspenders crew.

Yes, that's what I've done, but using a smaller device. I like the way you think.

[Moto]

I put it in behind the rear cover where the wires go in.  It was a small packet, about 1 inch long and 1/2" wide.

I think I see what you mean -- inside the case that contains the PCB, nestled in the square depression that accommodates the stepper motor? The size of the bag you fitted seems too small to me, judging from what I find in electronics packages, and on the assumption that the vents remain open. But it's better than nothing!

[Dilliw]

Could you cover the vents with this stuff?

http://www.gore.com/news-events/press-release/venting-protective-press-release-small-electronic-displays-us

[Moto]

Could you cover the vents with this stuff?

http://www.gore.com/news-events/press-release/venting-protective-press-release-small-electronic-displays-us

You could, and it might help, but it doesn't solve the problem too effectively, I think. The press release correctly describes how such water barrier films work:

"The VE80205 vent rapidly equalizes the internal pressure by allowing air to flow freely into and out of the enclosure. In addition, the breathable membrane that is incorporated into the vent reduces condensation by allowing moisture vapor to escape from the enclosure. At the same time, this membrane protects the electronics from liquids and particulates by providing a durable barrier that meets IEC’s IP67 standard."

Both "air" and "moisture vapor" pass through the vent and membrane. Moisture vapor escapes from the enclosure, as claimed, but only to equalize partial pressure of H20 with the environment. That is, it isn't differentially purged from the enclosure. In a dry environment this will be a good thing, but in a wet one it won't. The problem we face with the dash comes when the temperature drops, causing condensation. If the enclosure contains water vapor -- which it will, with this system -- condensation will occur at the dew point.

The benefit in protecting the electronics from liquids and particulates is marginal in our case, since the small vents are pretty protected by the location and their baffling.

Some membranes are even finer than the one offered here: they don't pass O2 or N2, but do allow H20 (a smaller molecule) to pass. These can be used in house construction, to allow water vapor to escape from buildings without loss of heat contained in the N2 and O2 components of air.

[Moto]

Moisture-Proofing the Griso Digitek Dashboard

Part 2. Adding a Desiccating Breather

Part 2 discusses the first of two approaches to controlling moisture in the dash. Since the dash must be exposed to atmospheric pressure and therefore must be vented, a breather containing a desiccant is connected via a hose to one of the vents. The goal is to make a very small-capacity breather, with a relatively tiny opening, since only very gradual changes in atmospheric pressure need to be accommodated. Anything greater would use up the desiccant too quickly. In the complete system the other vent is connected to another hose for periodic purging of any moisture build up. This design avoids opening up the dashboard proper, so I consider it to be non-invasive from an electronics point of view.

The parts diagram provides some terminology:



1. Dashboard ("complete")
2. Instrument frame (chrome)
4. Socket support
10. Lower dash cover (chrome)

Hoses are glued to the two small vents at the rear of the dashboard. They then run through (and are glued into) robust channels that were originally cast into the socket support in just the right positions! The lower dash cover, however, does not provide a passage for one of the hoses, so a hole must be drilled for it.

The existence of the channels seems to indicate a partially-completed project aimed at controlling moisture. I see no other use for the channels than to support hoses. However, the absence of any way for one of the hoses to go through the lower dash cover suggests the project was abandoned by the time the final design was completed.

Attaching the Hoses to the Dash

Here is a photo of the hoses glued to the dash vents and running through the socket support, before being glued to the latter:



After gluing up the assembly I tested it for air-tightness with a balloon and a stethoscope, plugging the second line with a cork:



I wasn't able to get a complete seal. It sounded like some air was escaping through the multi-pin plug, but not much.

This picture shows the hole I drilled in the lower dash cover for one of the hoses. It's the larger hole, made with a Forstner brad point bit in a drill press.



The Desiccating Breather

I decided on a clear glass fuel filter for the desiccating breather.



The breather is filled with color-indicating silica gel desiccant and zip-tied to the bundle of wires under the right gas tank wing. The right-side hose from the dash goes to the forward nozzle of the breather. The left-side runs in parallel along the same side and then loops back toward the rear of the breather. It attaches to a tee fitting which in turn is connected to the breather. The bottom of the tee is left hanging downward. The tee fitting has been modified so that the nozzle attached to the left-side hose is plugged; it functions only to seal that hose and hold it in position. The bottom nozzle has only a pinhole opening, feeding the breather.   The pinhole is the system's only opening to the atmosphere, and any air coming through it must pass through the desiccator on the way to the dash.

I purchased a 12v aquarium air pump to purge the system when it is being assembled and whenever the desiccant changes color, indicating it is exhausted or if condensation is ever observed.



Though I thought of permanently incorporating the pump into the system, and even bought an electronic humidistat-controlled relay, I decided in the end to make it a service tool that I insert in place of the tee fitting when needed, making a closed system in which the air is circulated through the desiccant. The pump is a loud little thing, and I wouldn't want it cycling on and off while I ride.

Current Status

I removed this system from the bike before ever using it, in order to pursue the second moisture-proofing method, a conformal coating. I encountered the conformal coating possibility only after I had pretty much completed the breather project, and gradually began to feel it would be superior. I'll probably re-install the breather just because of all the work I put into it.

Even though it is now a second-best option for me, it is a reasonable seeming approach that might appeal to those who might be hesitant to completely disassemble the dash to apply a conformal coating.

I continue to be intrigued by the partially-completed venting system I discovered in the design of the dash components.

Skip to:
Part 1. Theory and Dashboard Design 
Part 3. Applying a Conformal Coating
Part 4. Roy-Type Breather

[RinkRat II]

 Moto, I must commend your approach to this problem and the research you've done to get you to this point however, it seems to me you could pot the circuit board in epoxy made for just this purpose. Mask off your connection points , cover your stepper motor and dip or spray away. Been done this way for years in the industrial control world.( Backhoes,draglines,excavators etc).
  Just a different perspective.
     Paul B

[lucky phil]

The first BMW K100's suffered from the condensation issue as did my Triumph T595, both really quite badly. The fix for both? extra venting for the instrument case. The BM wasn't vented at all from memory and the Triumph had vents with baffles. I removed the Triumph baffles and vented the K100. Fixed both. Its mainly an issue when the temp changes quite quickly, so if the bike has cold soaked in the garage after the last wet/humid/wet and cold ride and then its pulled out on a sunny day they would have condensation issues.
Venting worked. There's no need for the instruments to be totally water proof just water resistant.

Ciao 

[Moto]

Moisture-Proofing the Griso Digitek Dashboard

Part 3. Applying a Conformal Coating

This part describes what's involved in putting a conformal coating on the Griso dash's PCB. It's an appealing approach to moisture-proofing, but the associated disassembly is challenging at points.

How Conformal Coatings Work

A conformal coating is a thin layer of a plastic applied to cover all suitable regions of a PCB. It is typically sprayed or brushed on as a liquid. The purpose is to prevent water droplets from collecting on the board, with the associated problems discussed in part 1. Interestingly, a conformal coating does not prevent water vapor molecules from reaching the PCB. As plastic, the material is permeable to water molecules. But if the coating is well applied so that it adheres strongly to the PCB, water molecules find themselves still trapped among polymer strands when they encounter the PCB, and so cannot collect together to form conducting droplets or pools.

It is important that conformal coatings be applied properly so that they do not bubble or otherwise become detached from the underlying surface when they dry. A thin coating helps to achieve this, and the military has a standard for these coatings requiring them to be about .003 inch thick. This kind of application would be hard to achieve without special equipment. However, hobbyists apply conformal coatings by hand, apparently with satisfactory results. I chose to use (I think) the most popular hobbyist material, an acrylic, shown here:



A comparison of different types of coating materials recommended this kind of product for situations like mine.

Conformal coatings are essentially invisible to the naked eye once applied, so a UV flashlight like the one in the picture is recommended for making sure coverage is complete. I paid about $10 for the UV light, and found it was money well spent.

How to Remove the PCB

The first thing is to remove the complete dashboard with its clear instrument cover from its mounting on the fork. This requires no special instructions. The instrument cover can be removed from the the dashboard by prying gently on the closing tabs around the edges. There may be some silicon glue to separate, and similar glue should be used on reassembly.

Removing the clear cover exposes the tachometer/instrument faceplate material. At this point the tachometer needle needs to be removed. An instruction I read on the internet worked well: Grasp the hub of the needle between thumb and forefinger and pull up pretty firmly and steadily. The hub should come up by an eighth of an inch or so and then stop. At that point, twist the hub counterclockwise against its internal stop while pulling gently upward. It will slowly twist off. I've done this twice now without incident. (EDIT: Looking at the smooth needle shaft in the photo, I think there is a bit of magical thinking going on in this removal procedure. But it works.) To reinstall the needle, make sure to position it to read zero when the stem has been rotated counterclockwise to hit the stop. Then push straight down. The post seems like it could be damaged easily, so deliberate caution is required.



The next step in getting to the PCB is to remove the three screws that attach the top and bottom halves of its enclosure to each other. Two of these will be found by gently bending up the two corners of the tachometer faceplate. The third screw is located 31mm from the edge of the faceplate in the direction of the 6 thousand rpm marking:



[EDIT: I now think the faceplate could probably be removed by inserting a putty knife from the edge and prying up around the central needle housing. I didn't do this because I was trying to avoid removing the needle. Only later did I understand the needle had to be removed anyway for access to the PCB. So the following paragraph about drilling a hole might be ignored.]

A small hole should be drilled through the faceplate using a brad point Forstner or other suitable bit. Then the third screw can be removed. (The hole can be covered with a small circle of electrical tape on reassembly. By the way, the little bonus hole in the photo was my mistake, even after measuring twice.)

The top half of the enclosure can then be withdrawn from the bottom. Turning it face down on a table, it looks like this:



In the photo two copper-colored projections connecting the PCB to the LCD display below can be seen in the foreground. These must be desoldered in order to remove the PCB from the housing. Techrat1 remarks that these are not metallic connectors, but copper-plated fiberboard, and require great care in desoldering. Use either a desoldering braid or a vacuum solder extractor. I confess I broke one of them. I replaced it on reassembly with a piece of desoldering braid, infused with solder.

The ribbon cable connector at the left side of the photo needs to be separated. It works like other cable connectors, though Techrat1 also comments on its delicate construction. The black bar seen across the top of the connector in the following picture amounts to a long wedge which can be pressed back away from the joint using your fingers on either end, releasing the ribbon. Take a moment to observe which side of the wedge is the top, so that you can more easily reassemble it later.



Now the PCB can be removed from its housing by pressing the tabs on the periphery outward.

Inspection, Coating, and Reassembly

Once the PCB is removed from the dashboard, it would be a good idea to carefully examine both sides, using a magnifying glass if nothing obvious is seen. You're looking for corrosion of course, but also very tiny dendrites (as shown in part 1). My own dash looked like new when examined by eye, and I neglected to examine it with a magnifying glass until the coating was applied and the board was resoldered to the LCD connectors. Looking closely at the ECU's connectors (which I estimate have an on-center pitch of only about 0.65mm) I found one suspicious particle about 0.3mm in diameter nestled against one pin. It's under the coating now, of course. I think it's a flake of dandruff, but wish I'd looked for it earlier.

The PCB should be painted with the conformal coating using the small brush attached inside the lid. A complete, even coat is desired, remembering not to cover open connectors (e.g., the ribbon cable terminals and the pins of the multi-pin connector) or anything else that might be damaged (in particular, don't cover the air pressure sensor). Make sure to do a good job on those closely-spaced connectors emanating from the CPU and other modules. I found surprising gaps when I checked the coverage with the UV light, which I then corrected. The bottle recommends a single coat.

After applying the conformal coating to both sides (and letting it dry) reassembly is pretty straightforward. Replace the board on the housing. Slide the ribbon cable into the connector and then wedge it with the black bar (right side up). Solder the two connectors from the LCD to the PCB, remembering they are fragile and are only coated with copper, not solid. Replace the screws holding down the faceplate and apply a patch of electrical tape over the hole. Press the tachometer needle on carefully, as described before, but don't press it all the way home yet.

Once the dashboard top and bottom enclosures are assembled and the tachometer needle is replaced, but before replacing the clear instrument cover, it is a good idea to see if the dashboard is working and then adjust the needle. Attach the two connectors from the bike's circuits while the instrument is just perched on the triple tree, and then turn on the ignition, while holding your breath. If it doesn't work at first, try reseating the connectors. If the needle does not read zero after it sweeps up and down in its starting routine, pry it up and reposition it. Press the needle all the way down on its post when you are satisfied.

Recommendation

I can't really recommend this procedure to anyone who fears trying it, because of the danger of screwing something up. I only went ahead in the spirit of exploration and because I figured I might be replacing the dashboard someday anyway if I didn't find a remedy for the moisture problem.

Please don't complain to me if you kill your dash!

Though a conformal coating seems to be an excellent treatment, I recommend the noninvasive breather as less dangerous to attempt.

Moto


Skip to:
Part 1. Theory and Dashboard Design 
Part 2. Adding a Desiccating Breather
Part 4. Roy-Type Breather

[Moto]

Moto, I must commend your approach to this problem and the research you've done to get you to this point however, it seems to me you could pot the circuit board in epoxy made for just this purpose. Mask off your connection points , cover your stepper motor and dip or spray away. Been done this way for years in the industrial control world.( Backhoes,draglines,excavators etc).
  Just a different perspective.
     Paul B

Thanks. See my last post in the original series, Part 3. Applying a Conformal Coating. Same idea. The challenge is the disassembly and reassembly of the unit.

[Moto]

Venting worked. There's no need for the instruments to be totally water proof just water resistant.

Could be, but I see dew on my well-ventilated grass just about every morning. All condensation counts, I think; the damage from corrosion, etc., is slow and cumulative. I suppose I'm trying for a really long-term solution -- so that I could regard my Griso more like I do my T3, as immortal!

[lucky phil]

Could be, but I see dew on my well-ventilated grass just about every morning. All condensation counts, I think; the damage from corrosion, etc., is slow and cumulative. I suppose I'm trying for a really long-term solution -- so that I could regard my Griso more like I do my T3, as immortal!

Well you got half of the equation, the condensing part, as in dew on the ground. The reason you get water on the inside surfaces of your instruments is due to evaporation and condensation. The moisture and moist air trapped inside the instrument getting warmed by the electronics inside and by rising engine generated heat. This evaporated moisture then condenses usually on the inside of the instrument glass and runs down the inside face then collects in the housing or the circuit boards etc and the cycle repeats itself.
The only way to control it is to hermetically seal the instrument with dry air or an inert dry gas or to improve the internal ventilation so the moist air has the ability to exit the instrument housing before it gives off too much water vapor that's looking for somewhere to condense.
My Ducati 1198 headlights ( pretty much fully sealed) used to fog up when the bike was new due to the moist air trapped inside the headlights getting warmed when the lights were turned on then condensing on the inner lens face.
I simply removed the bulbs and dried out the moisture with a hair drier installed the lamps again asap and it never happened again. Probably a very humid day in Italy when it was put together.

Ciao   

[Kiwi_Roy]

Excellent work Moto.
I like the idea of breathing through desiccant, it will absorb the moisture, thats what we do with lots of industrial instruments.

[tris]

My B11 is on its second set of clocks and I decided to try and fix it BEFORE it broke again!!

Rightly or wrongly, my assumption was that the electronics in the dash warmed the air up, which rose to the top of the clocks and drawing cold air in at the bottom which then condensed out on the face of the cold clocks. Usually manifesting itself after a ride and then a stop for a coffee

So I decided that the solution was to manage the ventilation of the clocks so I

• sealed any gaps round the edge of the clocks - stop any water driving in from the front
• fitted aquarium elbows to the 3 highest vents pointing downwards . The little labyrinth seal vents look to me that they were the 90 degrees out to prevent water running down the back of the clocks getting inside
• to the lowest vent I fitted a long hose that ends between the cylinders. The "theory" being that any air drawn in would be already warm so shouldn't condense out

The next option is to fit a 12v air pump to force the air to circulate. Could be simply ignition controlled or on a timer to keep going to (say) 10 minutes after switching the bike off

The jury's still out at the moment as since doing this I've not had any cold weather to ride in so can't say for sure that it works

I shall read everyone's thoughts on this subject with interest

[tris]

The lads on the Aprilia forum have the same issues - WHO KNEW!!

These are worth a read if you've not seen them before

http://www.apriliaforum.com/forums/showthread.php?138255-How-to-fix-those-f-oggin-gauges

http://www.apriliaforum.com/forums/showthread.php?185490-How-to-fix-those-f-oggin-gauges-part-deux
NOTE: The sticky Goretex repair patches referred to are NOT breathable

http://www.guzzitech.com/forums/threads/condensation-in-clocks-breva-griso.1892/page-2

[lucian]

Very interesting and detailed post, all in an attempt to help solve a real problem for all with one of these problem dashes, myself included. Hats off to you and thanks. Can't wait for the 24 hour ride in the pouring rain test results. 

you would think the dash manufacturer would coat these boards from the get go. It seems it may take the combination of your two approaches to solve both the fogging and the failure problems. My first dash was replaced under warranty and my replacement  I merely sealed all of the lens rim with bees wax and have not had another problem............ ...... yet.    All the best with your outcome.

[Dilliw]

http://www.apriliaforum.com/forums/showthread.php?185490-How-to-fix-those-f-oggin-gauges-part-deux
NOTE: The sticky Goretex repair patches referred to are NOT breathable

That seems strange that they wouldn't breathe given that's what they were designed to do.  The trailer lights that I bought the other day had them covering the  drain hole so maybe there's another brand out there that does?

[Moto]

The lads on the Aprilia forum have the same issues - WHO KNEW!!

These are worth a read if you've not seen them before

http://www.apriliaforum.com/forums/showthread.php?138255-How-to-fix-those-f-oggin-gauges

http://www.apriliaforum.com/forums/showthread.php?185490-How-to-fix-those-f-oggin-gauges-part-deux
NOTE: The sticky Goretex repair patches referred to are NOT breathable

http://www.guzzitech.com/forums/threads/condensation-in-clocks-breva-griso.1892/page-2

Yes, I've seen those. The first is trying to seal the enclosure, and second is showing how to add vents after many had had problems with the first procedure. The Aprilia dash that is shown doesn't have the air pressure sensor, so sealing it up would not hurt the engine calibration. I can't tell whether the castings for the OEM vents (on our bikes) are actually plugged in this particular dashboard -- I don't see the half-moon baffles, but it could be a lighting problem.

The third thread was where I found the idea of drilling holes through the faceplate to get at screws. But it's just another should-I-seal or should-I-vent thread, with little to be learned about a proper fix.

[Moto]

My B11 is on its second set of clocks and I decided to try and fix it BEFORE it broke again!!

Rightly or wrongly, my assumption was that the electronics in the dash warmed the air up, which rose to the top of the clocks and drawing cold air in at the bottom which then condensed out on the face of the cold clocks. Usually manifesting itself after a ride and then a stop for a coffee

So I decided that the solution was to manage the ventilation of the clocks so I

• sealed any gaps round the edge of the clocks - stop any water driving in from the front
• fitted aquarium elbows to the 3 highest vents pointing downwards . The little labyrinth seal vents look to me that they were the 90 degrees out to prevent water running down the back of the clocks getting inside
• to the lowest vent I fitted a long hose that ends between the cylinders. The "theory" being that any air drawn in would be already warm so shouldn't condense out

The next option is to fit a 12v air pump to force the air to circulate. Could be simply ignition controlled or on a timer to keep going to (say) 10 minutes after switching the bike off

The jury's still out at the moment as since doing this I've not had any cold weather to ride in so can't say for sure that it works

I shall read everyone's thoughts on this subject with interest

Your ideas seem sensible. In my part 2 of this set of posts (Adding  a Desiccating Breather) you'll see a picture of a 12v aquarium air pump with 1/8" (nominal) hose fittings. I could only find one on ebay, and it took a few weeks to ship from China. As I mentioned on that thread, it's pretty noisy, so be forewarned. You might consider adding a desiccating breather to a single vent, as I describe there.

Moto