Reverse lights non-functional

[deadlydave]

The Reverse lights in my '91 318is are not working right now. I've already replaced the switch and bulbs, to no avail. I have also checked the fuse, which looks fine. Is there anywhere else I should concentrate my search?

Pain in the butt, since I have someone coming by tomorrow that might want to buy the car. Briefly considered running dedicated wiring for just the reverse switch.

Thanks in advance,
-Dave

[Cephas]

Have you confirmed with a voltmeter that there's +12v getting to the switch? How about the harness connector under the shift boot? At the sockets themselves? Sometimes the connectors for the panel that the rear bulbs go into get corroded.

Happy hunting. Electrical issues are no fun, but with a meter, you can track this one down.

[Todd Black 88]

Have you confirmed with a voltmeter that there's +12v getting to the switch? How about the harness connector under the shift boot? At the sockets themselves? Sometimes the connectors for the panel that the rear bulbs go into get corroded.

Happy hunting. Electrical issues are no fun, but with a meter, you can track this one down.

Check that you have 12v at the switch. If not, pull the shift boot and look for the connector that feeds two wires down through the rubber boot around the shifter. Pull apart the connector and look for 12v on the chassis side of the plug.....actually, I would do this first so I don't need to jack the car up and climb under it.

[deadlydave]

Thanks for the direction, I'll look at the wiring going into the shift boot to make sure I'm getting 12v. I pulled apart the center console yesterday and took a quick look so everything will be easy to get to today.

[Todd Black 88]

I recently went through this exact thing. Ended up with making a new loom from inside to the switch, and it still made no difference. I pulled the switch, hooked it to the loom and it worked, put it back in the tranny and it did not work. Ended up getting pissed off and throwing the switch in the box with my original failed seal switch and noticed the old switch pin was 1/4" longer from the body.
I ended up dismantling the switches and noticed the inside of the old switch was milled out much farther then the new switch, so the pin stuck out farther. I drilled the body out 1/4" farther, dropped the pin in, stretched the spring longer to make contact, dropped the seal plate in, dropped the connector plate in and epoxied it back together.
Tested. And it works. First time in three years I have reverse lights.
Switch was from BMW dealer.

[e30topdown]

I recently went through this exact thing. Ended up with making a new loom from inside to the switch, and it still made no difference. I pulled the switch, hooked it to the loom and it worked, put it back in the tranny and it did not work. Ended up getting pissed off and throwing the switch in the box with my original failed seal switch and noticed the old switch pin was 1/4" longer from the body.
I ended up dismantling the switches and noticed the inside of the old switch was milled out much farther then the new switch, so the pin stuck out farther. I drilled the body out 1/4" farther, dropped the pin in, stretched the spring longer to make contact, dropped the seal plate in, dropped the connector plate in and epoxied it back together.
Tested. And it works. First time in three years I have reverse lights.
Switch was from BMW dealer.

Do you recall if the switches were the same part number, Todd?

[deadlydave]

Todd and Cephas, thanks for the help. It was indeed the wiring between the plug under the center console and the switch. I had started constructing a new mini-loom for just the reverse lights, glad I didn't have to follow through with that.

It was over 90 today with ball-soup humidity, so working under the car at least provided some shade.

[Todd Black 88]

Do you recall if the switches were the same part number, Todd?

Exact same part number. I don't know what the deal is with the one I got, but the pin stuck out less than the original. I bought it from my local BMW dealership.

[Todd Black 88]

Todd and Cephas, thanks for the help. It was indeed the wiring between the plug under the center console and the switch. I had started constructing a new mini-loom for just the reverse lights, glad I didn't have to follow through with that.

It was over 90 today with ball-soup humidity, so working under the car at least provided some shade.

Glad you found it.

[Zeltar]

anyone know the type of connector at the switch? seems to be dual blades but need to fabricate a new connection from switch to shift boot connector. I scored the white dual pin connector on the shifter side but need to figure out what's on the other side. also seems total length is less than 12"

thanks in advance....

[Todd Black 88]

E30 switch is just two female spade connectors, nothing special.

[Zeltar]

Great thank you. Wanted to confirm before I get her jacked up.