Okay, Today I decided to install Superbright L.E.D.'s in my instrument cluster. I used a special plastic socket from some direct replacement bulbs that were not bright enough, a resistor and, a signaling diode to prevent reverse current flow. Dash is much brighter now but on a test drive home after work I noticed the temp gauge was way high after driving maybe 5 miles. As I turned on my turn signal I noticed the needle peg and drop with the flashing of the signal. It didn't drop all the way but, down to 100c. I thought this was strange so I also turned off my head lights and the temp dropped lower but it was still higher than normal. I stopped at a store on the way home checked coolant level put my hand on the radiator hoses, warm but nothing too hot. After getting a few items I drove home and the temp gauge kept rising alll the way up to 120c.
Has anyone else experienced this, It's almost like the temp gauge is off. Is it maybe the bulbs I put in or did I nock a ground loose while I was messing with the dash? Please Help

I am curious about where you got the info to do that properly?
If you managed to figure that out, you should be able to read schematics for the system.
Sounds like you're in the right direction, grounds. But it would be nice if you posted your new plan.

With bad grounds, I noticed pulsations across the board, but the grounds were not IN the cluster. Also, dummy lights blinked as well.

__________________

Okay I have some news. It turns out that when I installed one of the bulbs I shorted out the socket. When this happened it burned a lead off one of the bulbs. Apparently it also burned one of the traces right off the circuit board! Anyway I still was not pleased with the lighting so I tried something different. Turns out it works great, here is a pic. It's nice to be able to see the gauges at night, even in the evening.


I also redid the climate control and added a boost gauge. I used blue to match the interior.

Nice, I am working on doing the same thing in red.

I was experimenting with hard wiring single LEDs into the instrument cluster. I made an amature mistake and let one of the leads ground out on the backing. It toasted something in the board, but worked fine when I got another. The LEDs ended up being WAY too bright, but I am on the right track. I just need to get some more LEDs.

__________________
My Primary Driver - '85 300CD - 4-speed conversion, 2.47 rear, lowered, euro headlights, rebuilding (not restoring so much)

Wife's - '08 Saab Sportcombi Aero

Riding a '03 Yamaha Warrior

Blue LED's? That'd drive me crazy. I'd probably use a yellow or dimmed white if it did it....which I won't, because the stock bulbs are plenty bright for me.

__________________
-diesel is not just a fuel, its a way of life-
'15 GLK250 Bluetec 118k - mine - (OC-123,800)
'17 Metris(VITO!) - 37k - wifes (OC-41k)
'09 Sprinter 3500 Winnebago View - 62k (OC - 67k)
'13 ML350 Bluetec - 95k - dad's (OC-98k)
'01 SL500 - 103k(km) - dad's (OC-110,000km)
'16 E400 4matic Sedan - 148k - Brothers (OC-155k)