Neutral Switch

[jackson]

After having to quit riding for almost two years (sold my Griso & Breva 750 due to worsening heart problems), I have recovered enough to get back on a Guzzi.  Didn't think it would happen............. .but it did. 
I was looking for a used, large block but an extremely clean, 2010 V7 Classic (loaded with extras) popped up, only 30 miles away.  The price was right and the owner even agreed to throw in a HF motorcycle lift table if I bought the bike.  Only thing that didn't work correctly was the neutral light.  It will usually work when the bike is first started and then quit working completely once the bike warms up.  I removed the neutral switch (a bitch to get at it for removal) and decided to replace it with a new one due to the erratic "works, then it doesn't" nature of the problem.  Replaced it...........put everything back together, complete with a new, correct, crush washer..........it worked........until the bike warmed up.  It would work when it was dead cold and then stop working when the engine warmed up for a couple of days and now it's not working at all.  Checked the connection at the top of the switch and it's fine plus it's a brand new switch.

Has anyone run into this on any model of Guzzi and if so, did you find the cause? 

Anyone have any ideas?  When the light comes on, it burns brightly.  I pulled the tank and checked for a chafed wire but didn't see anything that was being pinched, stretched, etc.  I can live without a neutral switch but if I can find the fix, I'd like to repair it.

Thanks in advance for any advice that anyone may offer.

[Chuck in Indiana]

Are you running the Redline pink milk shake in the transmission?

[jackson]

Are you running the Redline pink milk shake in the transmission?

Nope.  Took a look at the engine, gearbox and final drive oil before buying the bike plus the owner had partially filled containers of the fluids that he had put in the bike.

[Chuck in Indiana]

Nope.  Took a look at the engine, gearbox and final drive oil before buying the bike plus the owner had partially filled containers of the fluids that he had put in the bike.

Hmmm, dunno.

[sign216]

As I understand it the neutral light isn't working on a V7.  Used to work when the bike was cold.  However the bike still starts etc.  Do I have it right?

It does sound like a loose or bad connection.  I know you checked, but take a look at the wire diagram and see if there's other areas to look at.  I think on a V7 the neutral light is routed through the speedometer unit.  Although this unit is a complex affair, the multi-pin connector isn't too bad to undo.  You could take it off, clean it, and re-attach.

That's all that comes to mind.  Study the wire diagram.  Sorry, that's all I got.

[jackson]

sign216;  Thanks for the reply.
Yes, the bike starts and runs perfectly.  I couldn't ask for a cleaner, better sorted V7 than this one (except for the erratic neutral switch)
I pulled the plug on the back of the speedo unit earlier today and although there was NO buildup of anything visible, I sprayed it well with electronic cleaner and checked all the pins for corrosion (or a bent pin).  Nothing looked the least bit out of the ordinary. 
The wire comes from the spade connector that attaches to the top of the neutral switch (on top of the gearbox) and leads to a plug that has an additional wire from a larger harness. From there, I think (but don't know for sure) that those two wires go to the instrument cluster.
It has me totally stumped and I can usually find these types of things from wrenching on my motorcycles and cars since I was around 14 years old.  If I can't find it, it's not a big deal since neutral is easy to find.  I would just prefer to have it work (if I can).

[mgfan]

Ditto the connection. Where the wire is crimped onto whatever connects it to the neutral switch. Cold, wire contacts the crimp. Warms up, crimp expands, no more contact. Happens more than people realize.    :BEER:

[sib]

We must also consider the possibility that the new neutral switch is defective.  From what I can determine, the switch is supposed to be closed with the plunger out (in neutral) and open with the plunger depressed (in gear). Take the switch out, see if the resistance between the terminal and the shell is near zero, but rises when you push in the plunger.  Heat up the switch and then try it again.  Before you do that, warm up the bike, then short the neutral switch terminal to ground (engine case).  Does the neutral light go on with the ignition?  If not, then it's the wiring that's the problem.

[Chuck in Indiana]

I've had problems with an intermittent switch before. <shrug> It would test fine every time I tested it. Finally, a new switch cured the problem.

[jackson]

We must also consider the possibility that the new neutral switch is defective.  From what I can determine, the switch is supposed to be closed with the plunger out (in neutral) and open with the plunger depressed (in gear). Take the switch out, see if the resistance between the terminal and the shell is near zero, but rises when you push in the plunger.  Heat up the switch and then try it again.  Before you do that, warm up the bike, then short the neutral switch terminal to ground (engine case).  Does the neutral light go on with the ignition?  If not, then it's the wiring that's the problem.

I did this test with the old switch and the new switch using a heat gun.  The old and new switches worked whether they were hot or cold and activated the light.  It only malfunctions when it's inserted in the gearbox and it the bike warms up.  I have the correct crush washer on the bottom and I tightened it to around 5-6 lbs of torque.  Couldn't get a torque wrench in there but around 5-6 lbs is easy enough to feel.
It has me totally stumped.

[CalVin2007]

  It almost sounds like the switch is just <barely> making contact when cold and then when things warm up it isn't. I think I'd try shimming the switch up slightly with a bit thicker washer or shim, allowing the plunger to extend a tiny bit further. Alternatively you could shorten the plunger a bit if the design allows it. Could be the seat where the switch body sits was machined just a touch too deep at the factory....if so the shimming should help. That's what I'd do next anyway....

   Terry

[Chuck in Indiana]

  It almost sounds like the switch is just <barely> making contact when cold and then when things warm up it isn't. I think I'd try shimming the switch up slightly with a bit thicker washer or shim, allowing the plunger to extend a tiny bit further. Alternatively you could shorten the plunger a bit if the design allows it. Could be the seat where the switch body sits was machined just a touch too deep at the factory....if so the shimming should help. That's what I'd do next anyway....

   Terry

Worth a try.

[Bill Havins]

Terry's thought, above, makes good sense.  But I know "nothing" about the V7's electronics.

If the V7's neutral switch is like the Tontis, it provides a path to ground the neutral light.  So, I would "break the circuit" into sections and see where the fault lies.

If the V7 neutral switch does switch the circuit to ground, simulate the conditions when the neutral light just does not come on (warm the bike, etc.).  Then, pull the connector off of the neutral switch and connect a jumper between the connector and the engine.  If the neutral light does come on it is obviously the neutral switch.  If it doesn't come on it is an issue "above" that level (e.g., a bad contact on the bulb, a bad contact on the bulb socket, a problem in the wiring loom, etc.).

I am leaning toward Terry's idea (the need for a thicker crush washer to "lengthen the throw."  But I know nothing about the V7s.

Good luck!

[jackson]

  It almost sounds like the switch is just <barely> making contact when cold and then when things warm up it isn't. I think I'd try shimming the switch up slightly with a bit thicker washer or shim, allowing the plunger to extend a tiny bit further. Alternatively you could shorten the plunger a bit if the design allows it. Could be the seat where the switch body sits was machined just a touch too deep at the factory....if so the shimming should help. That's what I'd do next anyway....

   Terry

Thank you for the suggestion.  Removing the switch is real PITA due to it's location.  It takes around 30+ minutes just to remove everything that needs to be out of the way so I can access it better for a total removal.  I can just get to it enough to loosen/tighten it without removing everything so I just went down to my workshop and loosened it to varying degrees but the light still won't come on so I tightened it back but it still won't illuminate any longer.  I'll probably take everything apart and completely remove the switch one more time and see what I can find.  And if I can't find the cause, I'll just put it back together and forget about it.
Thanks for all of the suggestions.

[Kiwi_Roy]

As Bill said, with the key On touch the terminal with a grounded wire, If the light then goes it's the switch not making contact internally.

If the light doesn't go, then with the key Off measure the resistance between switch terminal and the chassis, it should read zero when in Neutral.

You should also read 12 Volts at the switch terminal if it's not in neutral proving the bulb is ok.

Sometimes you can have two faults at the same time, just try each item individually.

[jackson]

Ran the tests and the switch is okay.  The problem is somewhere between the neutral switch and the bulb.  I've had the tank off twice and cannot find any evidence of chafing along the harness.  I've also removed the plug to the speedo housing.  I'm not going to cut into the wiring harness so I've decided to just live with it and do without a neutral light. 
Thanks to all who offered suggestions for finding the problem.

[Bill Havins]

If you haven't done so already, when you have a calm moment or two, pull the instrument cluster apart far enough to look at the Neutral Light Bulb and its socket.  If it is anything like the setup on my '98 EV the problem may be as simple as a problem contact on the bulb, in the socket, or both.

Good luck!

[twhitaker]

You do realize that the neutral switch is only a suggestion anyway, don't you? It's there so you know you are in the right neutral rather than the other 4 false neutrals.  ::)  ;D