No brake lights, dash guages out, Climate Control not right. - PeachParts Mercedes-Benz Forum

Jetmugg · #1 10-16-2012, 07:59 AM

Good morning all:
I just got to work, and haven't had time to check any fuses yet, but anyway.... on my 190D, I just encountered an electrical issue that has affected my brake lights, dash gauges 9(except the tach, which still works), and the Climate Control system.

Your thoughts are appreciated.

None of the 3 brake lights are working. The fuel gauge, temp gauge, and oil pressure gauge are not working. The Climate Control will not turn "off", even when pressing the "0" button - the blower still runs and can be controlled by the fan.

Possible OVP relay problem? Fuse? Something else entirely? When the sun comes up a little more, I'll sneak out of the office and spend a little time looking in the fuse panel.

Steve

brandlj · #2 10-16-2012, 08:10 AM

I would check the fuse box first. Last week, fuse number 6 in my 86 300sdl cracked and I had no gauges, and no brake lights. Simple fix. Popped in a new fuse and all was right with the world. I do not know which fuse controls your gauges and brake lights. Hopefully your fuse chart is still in your fuse box.

Bob338 · #3 10-16-2012, 08:47 AM

Looks like a grounding issue to me. With a similar problem in the gauges and CC unit, I found corrosion in a couple places; the grounding strap between the frame and the bell housing, and corrosion in the instrument cluster. The latter relies on metal contact between the three units of the cluster that tends to get corrosion over time. In my case, cleaning those contact points with a pencil eraser and cleaning the contact points of that grounding strap under the car, took care of the problems. I'd also look at the grounding points for the entire car which are on the firewall behind the left AC vent.

These are all the ground wires on the firewall;

Jetmugg · #4 10-16-2012, 09:56 AM

Thanks, guys, for the quick responses. I really didn't have time to mess with it before work today.

It was fuse#9, which did not appear to be burned, but was cracked, and fell apart as I pulled it out. That explains why the instrument cluster didn't die a sudden death, but was intermittent in its failure, until it stopped completely. The fuse panel covers on these W201 cars are a real PITA to remove and re-install, if you didn't already know.