Help! Electrical trouble on 500SEL (1985)
 

Long story but here goes...I was replacing a light bulb in the climate control unit and accidently shorted it to ground just for a second (do not ask me how). I put everything back together and I had no dash lights at all, the fuel gauge pegs and the temp guage pegs They also jump when you turn the brights on. When I buckle the seat belt, the seat belt and bright lights warnings come on very dim.
I pulled the guage cluster and it smelled like something burned. I replaced the guage cluster (Left side) and the dimmer control and now I have dash lights but everything else is still happening. Did I burn some wireds together or is there an other suggestion?
Any help would be appreciated!
THANKS!

More than likely you have a two wires that have burned together or you have a burned a trace inside the dash. You will need an ETM for this car.

We sell the CD and the wiring diagram is in it.

cluster gages jumping
 

Hello,

Seems I have similar problem. But first, what is an ETM? What does the ETM acronym stand for?

I have a '92 300SD which goes haywire when I use the turn signals. This first started happening when I drove the car during a rainy evening. Almost everytime when I use the turn signals (or emergency blinker), the instrument cluster gage needles seem to get "shocked!" Seems as if the instruments reset because several gage needles jump / peg to a zero position and diagnostic indicator lights flash. The gage needles in question are:

1. oil pressure gage needle (and red light)
2. coolant temperature gage needle
3. fuel economy gage needle
4. safety belt light blinks (most consistent)
5. low oil level indicator lights up and turns off
6. battery indicator lights up and turns off
7. "exterior light bulb out" indicator
8. other indicators flash on and turn off.

All this happens at once only during the first 'blink' of the turn signal. If I keep the turn signal on, the gages go back to showing what they're intended to measure. Sometimes, however, with the emergency blinkers on, the needles continually reset with every 'blink.'
This behavior consistently repeats while driving but happens much less (rarely) when the car's transmission lever is in parking position.

I am clueless as to what might be the cause for such erratic behavior. I am 99.9% sure that it isn't caused by water, because I live in Phoenix, Arizona, and it has been at least 4 months since this first started happening. During this time, I've not driven the car in rainy weather at all.

I will very much appreciate any advice on how to diagnose and repair this problem.

Many thanks,

Branimir


'92 300SD (119K mi)
'82 300SD (295K mi)
'81 240D (126K mi)