NO POWER: windows, cigarette lighter, auxiliary fan

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My 1991 318i s52 swap recently lost power to several places recently...

My windows do not have power coming to the window circuit breaker. The cigarette lighter does not have power. The auxiliary fan switch (on the side of the radiator) does not have power.

Any ideas? I checked for blown fuses. I could always check again.

[me_john85]

Looks like they share the same ground G200. Googling it looks like it's somewhere by the driver's feet. Try measuring for power at the circuit breaker to the negative battery post. If you have power then start searching for that G200 ground.

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Okay, thank you for the tip. Any more information on the g200 ground location?

Edit: I found the G200. I took off a ground wire I had added for cruise control years back (cruise never worked, now removed again). I tightened the ground up well. I have power at the cigarette lighter, but still no antenna, aux fan, or windows.

Edit: http://manuz1.free.fr/6enligne/e30/e30m3_88.pdf Not super useful, but showed me a little something.

[me_john85]

Unfortunately I don't. I just googled e30 G200 and read a little bit.

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Bump, still no luck. Any major relay that could be causing an issue? No power to windows or fan. Cigarette lighter works and so does the antenna.

[Stanley Rockafella]

what about the radio?

[Link]

The radio has power. It is the window breaker and aux fan switch that do not have power. Checked all fuses and tightened what grounds I could find.

[me_john85]

The radio has power. It is the window breaker and aux fan switch that do not have power. Checked all fuses and tightened what grounds I could find.

Check for good power and ground at fuses 17 and 18. Pull fuses out and go from each fuse side to a good ground point. One side should have ~ 12v and the other should have good continuity to ground.

Also inspect the fuse box look for corrosion, broken solder, clipped wires etc. since these two fuses are right next to each other I suspect something going on here.

[me_john85]

Also if you don’t have it yet.

http://www.armchair.mb.ca/~dave/BMW/e30/e30_91.pdf

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I will check fuses 17 and 18 as suggested above. Thank you John85 for the manual. I will peruse that for further ideas.

Bump for other ideas.

[george graves]

Most cars have what's called a "unloader relay" - when cranking, it shuts off power to a bunch of power hungry stuff. Like lights, radio, cig power, and windows. It's there to take power away from those things while cranking - as you want your car to start. 99% sure this is what your problem is.

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Relay k5 and k7 in the fuse box appear to be unloader relays.

I think the Part # 601 484 1 375 474

Anyone know how I can test a relay? Or where I can order the relay? I cannot find it on PelicanParts

[XcvX]

Relay k5 and k7 in the fuse box appear to be unloader relays.

I think the Part # 601 484 1 375 474

Anyone know how I can test a relay? Or where I can order the relay? I cannot find it on PelicanParts

I'll preface this with the statement that I haven't tried this myself and do not have the technical knowledge to say with 100% certainty but a couple days ago I came across a fusebox diagram on this webpage https://www.e30gruppe.com/e30-fuse-box-diagram/ which included the following text:

"One thing you can always do to test a relay easily is if your Horn is working, put that relay from K2 into the Low Beam K4, or other slot which you’re trying to get working."

I am no help on where to track down a replacement, though.