Fuse 10 keeps popping....help me read the wiring diagram!

[BMWManiac]

I love turning a wrench, but I hate, HATE electrical issues!

So, with the amount of heat generated by the turbo and downpipe, I think I've might have melted a ground or wiring.

Symptoms:
-Fuel, tach, temp gauges in cluster all don't work (speedometer is fine)
-HVAC won't turn on, blower won't turn on
-Radio works, check panel works

Actions:
-Found fuse #10 blown. With car off, replaced fuse and all the above works
-Start the car, fuse #10 blows again

Looking in the bentley manual, I see that fuse #10 has a green/white wire that goes to the cluster and S212 (main harness behind instrument panel)

This is where I am confused. As I mentioned, I noticed some heat scarring on the main engine harness near the downpipe and that is where I figured the issue would be. I cut open the harness and didn't see any issues there, so I'm wondering if I'm going about this the correct way. Also, I don't see the blower fan/HVAC on fuse #10?

Would love to have working gauges for my drive to the vintage!

[george graves]

The Bentley is a poor diagnostics tool for electrical stuff. The e30 ETK is much better.

If it was me......I would pulling up the ETK for your model and year, to see what fuse 10 powers... Then I would unplug or disconnect everything connected to it, and plug one in at a time to see what is blowing the fuse.

It could be anything. With out looking at the diagrams I can't help too much. But the oxygen sensor heater is in the area of the down pipe...that is one of the things I would look at first.

[BMWManiac]

Thanks, George...will do

How does the C101 connector, disconnect? I have a replacement harness coming anyways and it would be easier for me to pull the wiring harness, and inspect all the wiring to see what happened

[george graves]

How does the C101 connector, disconnect?

It's a sit and spin kind of thing. Twist one way on the top, the other on the bottom. :-D

[BMWManiac]

It's a sit and spin kind of thing. Twist one way on the top, the other on the bottom. :-D

I tried last night and wouldnt work....overcomplicated things but got it to unfasten this morning:)

[BMWManiac]

I want to bump this.....I think I found the issue. My reverse switch in the transmission basically fell apart, leaving my reverse wire connectors touching each other.....

While researching the reverse light switch, that I now need, I read to check fuse #10! So I think I might have found the culprit.

Now, having said that, where do the lines to run from? The shifter console to underneath the dash? I want to make sure the wires are fine as well.

[jlevie]

The wires for the reverse switch run under the console and down through the rubber shifter boot.

[BMWManiac]

The wires for the reverse switch run under the console and down through the rubber shifter boot.

I figured as much....would you happen to know if they are secured by a zip tie on top of the transmission tunnel? I'm curious if I can pull them back through or if it is hard to with the transmission mounted!

[M-technik-3]

I want to bump this.....I think I found the issue. My reverse switch in the transmission basically fell apart, leaving my reverse wire connectors touching each other.....

While researching the reverse light switch, that I now need, I read to check fuse #10! So I think I might have found the culprit.

Now, having said that, where do the lines to run from? The shifter console to underneath the dash? I want to make sure the wires are fine as well.

That's it. It is a very common issue. Short to grounds cause it to blow immediately.

[BMWManiac]

That's it. It is a very common issue. Short to grounds cause it to blow immediately.

Good, I replaced my main harness because of this and an ICV issue I am having with my MS2 setup....

[hyperE30]

I figured as much....would you happen to know if they are secured by a zip tie on top of the transmission tunnel? I'm curious if I can pull them back through or if it is hard to with the transmission mounted!

Glad you found the problem, same happened to me with a Vert I bought a while back, the wires for the reverse light run on top of the tunnel then under the carpet by the driver seat and then straight to the fuse box, take kick panel off and make sure the wires are OK to there. My wires when they touched melted another 4 wires.

[BMWManiac]

Glad you found the problem, same happened to me with a Vert I bought a while back, the wires for the reverse light run on top of the tunnel then under the carpet by the driver seat and then straight to the fuse box, take kick panel off and make sure the wires are OK to there. My wires when they touched melted another 4 wires.

Great....did I mention how I love wiring!

[MrSlacker]

WOAAA!!!

My fuse #10 started randomly blowing one day. Would happen sometimes after an hour of driving, sometimes after 20min or it was fine.

Then after a week it has been just fine. I recently noticed that my reverse lights don't work!

Now I am getting random check engine light that goes away right away.

Going to try a new switch and check the wiring as well... THANKS!

[BMWManiac]

WOAAA!!!

My fuse #10 started randomly blowing one day. Would happen sometimes after an hour of driving, sometimes after 20min or it was fine.

Then after a week it has been just fine. I recently noticed that my reverse lights don't work!

Now I am getting random check engine light that goes away right away.

Going to try a new switch and check the wiring as well... THANKS!

Yes, check the switch (passenger side of trans) and you should see two wires to connect to two prongs on the switch!

[MrSlacker]

Turned out my reverse wires were completely cut in half somehow! Hopefully fuse 10 will no longer be an issue