Power windows only work when driver door is open?

JFENG

JFENG

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1974 USA market 3.0CS

I believe this was discussed previously but I can’t find the thread, and my crappy memory prevents me from recalling the ah-hah info about this problem.

Symptom: power windows only work when driver door is open. Opening passenger door has not effect. This started a couple years ago (I’ve had the car for much longer). Perhaps related to this is the dome light doesn’t come on when the door is opened, but it will light up when the switch on the dome light is in the “always lite” position. I pulled the driver door switch and notes that it is wired hot, and not as a ground. I don’t recall any of my E3’s wired that way but maybe it’s that crappy memory again.

Anyway, could someone like Arde or HBChris point me at the thread that explains the relationship between power windows and door light switch?

John

Ps: the reason I’m dicking with this is - helping bavbob with a few things on his Taiga coupe has reminded me that I’ve neglected my coupe (in storage), and need to give it some love. The b fluid needs a flush and the last registration was from 2017. I guess it’s a sign I have too many cars...
 
Mid 73 with newer motors and circuit breakers allow windows to work only with driver door open or key is on. The driver door switch has two terminals for this, pushing it in you can hear the relay clicking under the dash. Don’t know if earlier coupes do this. Clean the contact on door switch to improve ground and dome may work.
 
Chris

Thanks. So the problem is with the key-on operation not energizing a relay which provides power to the circuit breakers.

IIRC, the door switch grounds when the door is opened. I’m guessing that it’s either a nan wire between the two relays that feed the circuit breakers or the ‘second’ relay is bad.


Chris, thank you very much.
 
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It was a bad relay. I was initially thrown off because i tried my spare relay without success. Turns out my spare was bad.

The dome light was due to a little corrosion at the dome light switch itself. But I cleaned up the door contact per your suggestion as it was barely functional. The way BMW used those load shedding relays is pretty creative (non-obvious).

Anyway, Giving Bavbob a hand with his Taiga CSI has gotten me motivated to get my E9 done next. These are such nice driving cars. Not sporty, just a really nice 1970’s GT experience. My XK120 will just have to wait another couple years.

John
 
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Nice to see you got your priorities straight :cool:

bfeng said:
It was a bad relay. I was initially thrown off because i tried my spare relay without success. Turns out my spare was bad.

The dome light was due to a little corrosion at the switch itself. But I cleaned up the door contact per your suggestion as it was barely functional. The way BMW used those load shedding relays is pretty creative (non-obvious).

Anyway, Giving Bavbob a hand with his Taiga CSI has gotten me motivated to get my E9 done next. These are such nice driving cars. Not sporty, just a really nice 1970’s GT experience. My XK120 will just have to wait another couple years.

John
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Stevehose said:
got your priorities straight
Click to expand...

GTV comes first though. For me, Alfa’s trump anything BMW made between 1950-1970.

The 1970-80’s were the most interesting BMW years for me: CSL, tii, the pre-badge engineered M car’s M1/M3/M5/M6.

By the 1990’s BMW was starting to remind me of Mercedes (bigger, heavier, too complex). But jnthat same period the Japanese finally got it right (NSX, RX7 gen3, 300ZX TT, and of course the Mx5).
 
HB Chris said:
Mid 73 with newer motors and circuit breakers allow windows to work only with driver door open or key is on. The driver door switch has two terminals for this, pushing it in you can hear the relay clicking under the dash. Don’t know if earlier coupes do this. Clean the contact on door switch to improve ground and dome may work.
Click to expand...
I thought it was 74 but Chris knows. The changes BMW made were pretty dramatic with the relays. I have a 72 and needed all kinds of help with a 74. Way over my electrical pay grade. Bmw's are known for corrosion issues with fuses and light bulb sockets so watch out there as well.
 
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