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87 M6 wiper fuse blowing

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emac
Posts: 18
Joined: Thu Feb 06, 2020 2:57 am
Location: SC

87 M6 wiper fuse blowing

Post by emac » Sun Feb 09, 2020 8:54 pm

Hello,
I am new here and to the e24 car but I have owned and worked on many other BMW's. I just purchased an 87 M6 and I am sorting out a few issues. Wipers do not work and the fuse keeps blowing as soon as I turn the key on. I have disconnected the wiper motor and removed the K10 relay. Fuse still blows. I am thinking it is in the steering column. The previous owner had mentioned that the horn would randomly blow and he disconnected the horns. I am going to take a look inside the column and see if I can see any wiring issues that jump out at me. If anyone has any thoughts or even tell me I am way off in my thinking please let me know. My skin is thick.

I have already used this forum a ton for some other issues, like the steering box bracket and speaker removal. Thanks for the great info.

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hornhospital
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Location: Silverhill, AL

Re: 87 M6 wiper fuse blowing

Post by hornhospital » Mon Feb 10, 2020 12:02 am

Welcome to the maddness that is E24 ownership!

I believe you have already figured it out even without looking. The wiper switch or wiring harness in the steering column is almost certainly where the problem resides.
Ken Kanne
'84 633CSi "Sylvia"; '85 635CSi "Katja";'85 325e "Hazel Ann";'87 325is "Odette"; '93 325is "Elvira"; '95 M3 "Ashlyn"; '95 318is "Bebe"

emac
Posts: 18
Joined: Thu Feb 06, 2020 2:57 am
Location: SC

Re: 87 M6 wiper fuse blowing

Post by emac » Mon Feb 10, 2020 1:19 am

Thanks for the reply. Looks like it is something deeper. I unplugged the wiper switch at the steering column, removed the wiper relay (k10), unplugged both washer pumps, the wire going to the nozzle heaters, and the wiper motor. Still blows the fuse. What else could possibly be on the circuit? Is there another relay?

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86_6series
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Location: West Nyack, NY

Re: 87 M6 wiper fuse blowing

Post by 86_6series » Mon Feb 10, 2020 12:32 pm

The fuse #5 is dedicated to only the wiper and washer pump-heat circuit.
So no other device to worry about.
The horns are fuse # 7 separate circuit not connected to wipers, different problem or
something in column triggering both shorts.
The wiper circuits are on pages 0607-7
Ground circuits page 0670-15
Overall page 6160-0
Heaters on page 6160-1
Troubleshooting pages 6160A-1,2,3.A
I think that reading the trouble shooting helps understand the circuitry.

http://wedophones.com/Manuals/BMW/1987% ... Manual.pdf

I would do continuity tests (without power of course)
on all circuit wires.

good luck

emac
Posts: 18
Joined: Thu Feb 06, 2020 2:57 am
Location: SC

Re: 87 M6 wiper fuse blowing

Post by emac » Mon Feb 10, 2020 5:59 pm

Thanks. After sleeping on it overnight I have it sort of figured out. The wiring diagram I was using (bimmertips) has different fuse numbers than the manual! Plugged everything back in (originally the wiper motor plug was unplugged) and the wipers work fine. I think the PO unplugged it when he was detailing the car and forgot to plug it back.

The fuse that keeps blowing is actually the Defrost, according to the manual. Heat and AC according to the diagrams, that is the BMW electrical troubleshooting guide. So, I need to find the proper electrical guide for the car! I will check out that link. PO also gve me a BMW CD. Should be easier to fix knowing which circuit I am actually working on. :)

ernest

emac
Posts: 18
Joined: Thu Feb 06, 2020 2:57 am
Location: SC

Re: 87 M6 wiper fuse blowing

Post by emac » Mon Feb 10, 2020 6:45 pm

It seems the 1986 Csi electrical diagrams match my 1987 M6. i was using the 1987 diagrams and some of the circuits are in different locations. The wrong diagram along with a randomly unplugged wiper motor was like doing a puzzle without the box top!

On to figuring out why the defrost fuse is blowing! Thank you for the replies and a big thanks to the board for the steering rack fix from Ed Raether, I have one coming.

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