First MB - A W201 (190e 2.6 auto)... and I've got electrical gremlins... I need help! - PeachParts Mercedes-Benz Forum

PzKfWagen · #1 10-08-2007, 02:09 AM

OK, here's my story:

I bought a 1991 190e 2.6 with 160k miles on it. It runs great, shifts great, and steers great. I only have a few issues with it, but these I have no definite idea on how to fix them, although I've spent some serious time researching / pouring over wiring diagrams. Thus I turn to those more knowledgeable than myself.

1st problem:

Pretty much all of my interior lights don't work. What does work: The instrument cluster does light up, along with the rear dome light switch, the rear defrost switch, the seatbelt warning display / front dome light.

However, all the rest do not light up. No outside temp LED light (although the temp displays), no shifting pattern, no climate control, no window switches (front console or rear doors), no trunk light, no glove box light, no ashtray light, no moonroof switch light.

The rheostat does work on the lights that work (instrument cluster, etc) and the fuses all look good (not visibly blown). The car has had an aftermarket radio put in and it looks like some audio equipment unplugged in the trunk of the car, and the fader switch at the console is unplugged as well.

2nd problem:

The right rear window does not roll down, although the motor works well when 12v is put to it. When the door is open, when either the front or rear right rear window switch is pressed, it blows the fuse that controls that circuit. When the door is shut, the window switches don't work at all. Furthermore, when the right rear window switch in the console is plugged in, the front left window won't roll down either, although that does not blow a fuse when tried to roll down. I've resorted to disconnecting the right rear window switch to keep the left front window working.

Any ideas guys? I really need some help here.

CamelotShadow · #2 10-08-2007, 02:57 AM

check your fuses...

PzKfWagen · #3 10-08-2007, 06:35 PM

Fuses are ok, I checked both sides of each fuse holder with the ground on the body and I have good continuity when the appropriate switches are on (headlight, headlight hi beams, etc).

The problem is somewhere else.

eagle-co94 · #4 10-08-2007, 09:51 PM

PM me if you end up needing anything for your car. I'm in the process of parting out a 91 190E 2.6. Pretty much the whole car is there... except the passenger side doors and A-pillar that was crushed). I'm half tempted to bend out the b-pillar, put 2 doors on it and drive it.

Jim Anderson · #5 10-09-2007, 12:45 AM

Check your grounds (again for effect.) Sprinkled throught the car are places bolted to the body where lots of wires are plugged in. Locate and check them. General rule of thumb: if "funny" things are happening, its a bad ground.

PzKfWagen · #6 10-09-2007, 12:51 AM

Quote:

Originally Posted by Jim Anderson

Check your grounds (again for effect.) Sprinkled throught the car are places bolted to the body where lots of wires are plugged in. Locate and check them. General rule of thumb: if "funny" things are happening, its a bad ground.

Thanks, Jim. I've looked up some wiring diagrams and it appears that there's a ground for a lot (but not all) of the malfunctioning lights at location G202, behind the left side of the instrument cluster. Is this a common faulty ground?

CamelotShadow · #7 10-09-2007, 01:11 AM

Good Luck...

PzKfWagen · #8 10-09-2007, 01:14 AM

I need that or some serious electrical wizarding.

CamelotShadow · #9 10-09-2007, 01:20 AM

we all could use some luck
there are good helpful people here

Guess you'll need a test light.

I don't know
but I've had those gremlins

luckily mine just went away of there own accord

jeff-abalone · #10 11-25-2007, 03:29 AM

I have the same problem on my new 1991 190E too! No outside temp LED light (although the temp displays), no shifting pattern, no climate control, no window switches (front console or rear doors).... Anyone know what happened? thanks

PzKfWagen · #11 11-25-2007, 12:34 PM

OK guys, I got an update saying someone else was having the same problem, so I thought I would post to tell what happened and how I fixed it.

Basically, in my case, the wires in the rubber elbow leading from the door frame to the rear passenger door wore through their insulation and shorted together. Since there is an illumination wire that is one of those four wires, it blew a fuse. This fuse is between the general illumination output from the rheostat but after the internal instrument cluster illumination. That is why your instrument cluster lights up but nothing else does. BUT, this fuse is not, repeat NOT, in the fuse holder or any accessory fuse panels under the hood. It is a tiny circuit board fuse screwed into the rear of the instrument cluster, very similar to the lightbulb sockets that are screwed in, except it is red. It is located to the drivers side of the rear of the instrument cluster, in the center. Let me tell you that this was not easy to track down.

What I had to do was: repair the wiring in the door (took the door off and butt connected them damn wires), then drive the car on ramps, disconnect the speedo cable to get slack to remove the instrument cluster, then use a pair of coat hangar pullers to remove the instrument cluster, then go down to a MB dealership and buy the fuse ($5 or so and they may have to order it), then screw it in and voila! it worked.

Now something to keep in mind: some cars did not have a fuse in the instrument cluster, and the printed circuit board that backs the instrument cluster simply burned some of the printed lines out. In this case you will either have to get a new instrument cluster or you will have to do a solder patch job. If you need a new instrument cluster, I have one that works and has the spot for the fuse, selling it for $40 (cheap) to help whoever might have this issue. Email at panzerkampfwagon at hotmail com if you are interested.

Good luck guys, and hopefully this will help people in the future.

shingleback · #12 11-25-2007, 08:10 PM

Lack of shifting pattern and climate control lights, along with fan speed switch light could be burnt out lamps. There are little light bulbs that go into here. These are lamp #2721, which are 12V, 1.2W

The RR window problem sounds like a short in the door harness, since the symptoms change depending on whether the door is open or closed (broken wire or shorted to ground, depending on the door's position).