850T Warning Lights LED problem SOLVED

[swooshdave]

I had some leftover LED bulbs from when I upgraded my Triumph.

The instrument lights are a 194 and I only had one green LED. Looks cool but I won't use it. I went with red on the Triumph and they work really good at night. Not distracting and bright enough.

I had some 74 LED bulbs and when I plugged them into the neutral light socket they smoked and burned out. Plugged the incandescent in and it works fine. I wonder what I'm doing wrong.

I really want the neutral light to be way brighter.

[rodekyll]

You need to add a resistor to the line.  I have an array of them I use to stop the smoke from coming out and they also dim the bulb down.  I choose among the array for the best light and add that resistor to the circuit.

[swooshdave]

I have resistors. Where do you put then in the line?

[Kiwi_Roy]

Many of the OEM Guzzi bulbs have a single sided contact, if you plug a 74 in with the double sided contact it will short out the holder. This is the case for the T type dashes on VII models, Jackals etc.
I can't speak to your 850T but it may be the same if it has push in bulbs.


I prefer the 194 bulbs because they have a built in rectifier so polarity is a non issue
I discard the socket and solder the wired direct to the bulb, LEDs will outlast me and probably the rest of the bike.

[swooshdave]

Many of the OEM Guzzi bulbs have a single sided contact, if you plug a 74 in with the double sided contact it will short out the holder. This is the case for the T type dashes on VII models, Jackals etc.
I can't speak to your 850T but it may be the same if it has push in bulbs.


I prefer the 194 bulbs because they have a built in rectifier so polarity is a non issue
I discard the socket and solder the wired direct to the bulb, LEDs will outlast me and probably the rest of the bike.

I need better lighting in my garage so I can see these things. What you provided was brilliant! I would have figured it out sooner or later after going through 10 more bulbs. 

[Groover]

I used these for my '81 G5 dash bulbs (I only used them for the turn signal indicator bulbs).

https://www.superbrightleds.com/moreinfo/miniature-wedge-base/74-led-bulb-1-smd-led-miniature-wedge-retrofit-car/227/

I didn't have any problems other than being sure the polarity was correct for them to light up. Did I get lucky, or are the sockets different on the older T3 models?

[swooshdave]

I used these for my '81 G5 dash bulbs (I only used them for the turn signal indicator bulbs).

https://www.superbrightleds.com/moreinfo/miniature-wedge-base/74-led-bulb-1-smd-led-miniature-wedge-retrofit-car/227/

I didn't have any problems other than being sure the polarity was correct for them to light up. Did I get lucky, or are the sockets different on the older T3 models?

That is the assumption.

[swooshdave]

https://www.amazon.com/dp/B018LULLYY/ref=wl_it_dp_o_pC_nS_ttl?_encoding=UTF8&colid=26Y5AVMGX9WC6&coliid=IFVRHJYDC6KQK&psc=1

These bulbs seem to come with only one wire per side.

[Kiwi_Roy]

Yes but would fit in the holders
 
The Guzzi lamp fitting is for a 74 single sided bulb I think
The 74 seems to be all double sided, I chatted with Superbright's technical guy, he said "just clip the wire where it wraps over the end of the base", I guess they get asked all the time.

I still think throwing away the holder and soldering the wires direct to the lamp is better.
A pair of forceps makes it easy

[swooshdave]

Instead of hard wiring it I might be tempted to replace the sockets with the correct ones. It wouldn't cost anymore and would still give you the flexibility of replacing a bulb. In theory LED bulbs should last forever... in practice...

[Kiwi_Roy]

  In theory LED bulbs should last forever... in practice...

...a very long time, it's easy enough to solder a new one in
I did try lampholders for the 194 lamps but with any tension on the wires they would break contact.
If you want to stick with holders just cut the wires off the 74 lamps as mentioned.

You need to add a pair of diodes to the single 74 indicator lamp, the 194 has them built in.

The main complaint I hear about LEDs is they are too bright at night, they can be dimmed with a suitable resistor. The oil pressure can come on too in the rain, usually just requires a good wipe of the switch or some CRC.

I almost forgot, for your old Bosch Alternators the charge lamp needs a resistor in parallel to excite the rotor something like a 20 Ohm 2 Watt Ceramic.

For the thermistor type fuel level sensor leave one of the old lamps in parallel, you can see it in the picture I posted across the bottom lamp covered in heat shrink.

[swooshdave]

Actually I'm only going to replace the neutral light as that's hard to see in the sunlight and the two instrument lights because they burn the most. The generator and oil pressure light should, hopefully, rarely be on.

[swooshdave]

I snipped the wires per the instructions above.


Before


After

No mistake when it in neutral even on a sunny day. Just used a white bulb. A yellow one would turn it back to an amber. I'll try it out in the daylight and see if it's needed.

I'll order some red bulbs for the instruments next.