Temperature Gauge/dash board lights

I found 3 dashboard lights failed to function about a week after I pulled the bike out of my workshop. They had been fine when I tested the bike previously. The neutral, oil, and side stand warning lights all seem to have failed at the same time. Thinking it very unlikely that all 3 bulbs would have burned out together, I still decided to pull the dashboard apart (an onerous task) to check them and found all were fine. This leads me to believe there must be a bad ground, but do all 3 have a common ground? I'm trying to decipher the wiring schematic in my Haynes manual, but I am very colour challenged and it looks to me like a colourful explosion in a spaghetti factory. Any tips on what and where to look?
While I had the dash apart I decided to replace the temperature gauge, which has not worked in the time I've owned the bike. Since the fan has switched on occasionally, I haven't been worried about overheating. But since I was in there anyway!!! Seems that part # 37400-MT3-003, has been discontinued. The local dealer did a search among other dealers, and none were found. I then stopped by the local Suzuki Dealer and they did a search on their "Parts Finder" site, and no luck there either. Later model ST-1100 temperature gauges have a different part number. I was hoping they might be common among all years, but apparently not. Had anyone replaced the stock gauge with an aftermarket one that will fit and work, or do newer model gauges work, but Honda is just being coy about their numbers? Appreciate any help/advice you can give. Once I sort out the light problem, if a replacement gauge is not available, I will just re-assemble everything and ride the bike again anyway.
Thanks.

Silly question, but did you check the "A" fuse in the fuse box? Those lights are all on the same circuit. The Haynes colored wiring diagrams are the beST/easieST to use.

Sorry, can't help with the gage. Might juST be the sensor/sender...?

John

I'm pretty sure you could use any year gauge, as they all fit into the same dash location and the only differences I have ever seen were in the markings on the face plate. A lot of 1990 parts are now shown as obsolete because Honda isn't going to supply parts forever, but sometimes you DO find the part still available for more recent years. Sometimes part numbers will also change for no apparent reason. The OEM oil filter has changed numbers at least once, but it still looks the same.

The bulbs in question have the two thin wires sticking out of the glass bulb and sometimes those will, over time and vibration, lose contact with their socket connections. My clock bulb did that once and it just required carefully bending those wires outwards a bit to re-establish a good contact. Having three do it all at once IS unusual, but I would check that first before digging deeper.

I have a spare temp gauge. Well two actually. I have an early model and a later model. I can ship one to you but it won't happen till after May 8th as I'm on the road.

I followed the diagnosing instructions in the Haynes manual and the Sensor appeared to be OK, but the gauge was faulty, according to the book. I guess I can get the local dealer to order me a new gauge
from a year or two newer model, if still available, and hope it fits and works. If it's only the look of the face plate, no big deal, as long as it functions. If that approach doesn't work, then I can contact KILTMAN about sending one of his spare gauges. Appreciate the input.
RE: lights, I'll recheck the tiny little ends. I pulled ALL the fuses and using a continuity meter checked each one and they all are were good, but after I check the wires up front, I'll substitute a new fuse just in case.
Thanks for all the help, and I'll report back once (IF !) I get things sorted.
CHEERS

The reason I had spare gauges is I thought mine was a problem too. I found one on ebay. The input I received on the forum was that the gauges rarely go. In the end I had a ground issue. Try connecting a jumper wire from the ground terminal on the gauge to a good ground on the frame.
Just to remind you I have a small window of opportunity to ship one out to you so let me know by May 8th. I'll PM you with my email address.

Thanks to KILTMAN in Stratford Ontario I received a replacement Temperature gauge. I finally got that giant black plastic puzzle back together and all seems well. I cleaned the side stand switch with contact cleaner and used dialectic grease on it, and the dashboard light issue 'seems' to be solved. Thanks for all the advice and suggestions. Now I just have to find the money to get some insurance and off we go for another season.
CHEERS