Electrical gremlin?

[InNeedOfBoost]

Ok, for starters...I have a 91 318is. Has the VDO gauges. Since I've owned it the cluster gears have been shot...no biggie.

As of tonight, the only thing my cluster does now it light up and the speedometer works. None of the other needles work. The signal indicators work fine and when I start the car the Battery and Anti-lock indicators still come on. All of this happened as I was driving...I noticed two things happen...1) I saw my tach fall to zero and my fuel/ temp needles drop and 2) the blower motor switched off. I had the heater on full blast and that's why I noticed it, just turned off completely even with it on "4"

I thought maybe the cluster batteries failed but the blower motor not working right at the same time makes me think otherwise.

Any ideas? Help!!

[jlevie]

Check all the fuses.

[InNeedOfBoost]

Checked fuses this morning. The number 10 (7.5a) that controls the cluste, OBC and reverse lights was blown.

I put a brand new 7.5a fuse in it and it popped as soon as I started the car. I tried a slightly larger fuse (10a) and it did the same.

Still at a loss of ideas here...electrical is my weak point when it comes to cars.

[ForcedFirebird]

You will have to find the short and repair it. Bad practice to put larger fuses in, the circuit is only meant to handle the designated fuse size and you can burn wires when putting in larger fuses.

[InNeedOfBoost]

Thanks. Like I said...I suck with electrical, lol. I'll have to recruit one of my electrical buddies locally.

[jlevie]

A common problem that will cause that fuse to blow is a short in the wiring for the reverse light switch, usually under the center console (or between there and the reverse switch on a manual transmission).

[ForcedFirebird]

A common problem that will cause that fuse to blow is a short in the wiring for the reverse light switch, usually under the center console (or between there and the reverse switch on a manual transmission).

I have actually had a car come in that had that issue, he jumped the fuse with a paper clip and fried the body harness. That was a 3 day repair job.

OP, take your shift boot off, there's a pair of wires under there that go to the reverse switch. There's a little 2 prong plug there you can disconnect and try another fuse to see if that is the short.

[InNeedOfBoost]

I tracked down the issue finally! I didn't know where the reverse sensor was, looked it up in the Bentley. Got under the car to check it and the plug is there in the trans, but there's nothing connected to it. Found the reason my reverse lights have never worked since I got the car.

So, that wasn't my issue. Started looking thru the Bentley some more about the fuses. The #10 was the one that kept popping. That fuse is also tied into the On-Board Comp which ties into a bunch of other fuses. Double checked all of those again, found nothing.

Decided to replace each of those fuses one at time anyway and found that the #21 fuse was also blown, just couldn't see it. Where it was broken was close to the corner so it was out of sight.

So about 8 blown fuses later...its fixed. What a pain, lol.

[bmwguy325is]

For future repairs. A test light can save you a lot of time when checking fuses.

[InNeedOfBoost]

Yea, I need to quit being lazy and get another.

[Gregs///M]

Unplug the OBC and cluster and see if you continue to blow fuses or pull more current that 7.5 amps. There could be a short in the wiring, perhaps related to after market radio, which installers often "tap" into OBC wires, when they shouldnt.

[InNeedOfBoost]

Lol, look up a couple of posts..I figured it out.

Thanks anyway.