E36 Reverse lights not working

Checked fuses and it shows 13v Checked wiring for damage in the rear not damage found Checked bulbs their good. Checked voltage across the bulbs which there is not when car is in reverse.

I'm thinking it's the reverse light switch but would love to know how to check this

BMW 316i E36 1994 Manual

Any help???

Mar.

Reply to
Marian Given
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On Wed, 28 Feb 2007 09:23:00 +0000, Marian Given waffled on about something:

Odds are it's the switch.

It's on the side of the gearbox (I assume you're UK as you've got a

316), IIRC it's on the passenger side of the box. Look for a big 26mm+ nut with a connector... That'll be the one.

It's quite easy to change, but you'll have to get under the car.

If you want to check it, put the car into reverse, then get underneath. Take the plug off the back of the switch and you should find 2 connectors, put a multimeter across them. You should see a dead short when it's in reverse.

You don't need the engine running, or ignition on for this, in fact put the keys in your pocket for safety!

Hope this helps

Dodgy.

Reply to
Dodgy

My '94 E36 has this same trouble. I get 12v to the lights when the lights are not installed, but the voltage goes away if the lamps are installed.

I think the trouble here is that the switch is dirty, very dirty. Voltage in a circuit is dependent upon the volts applied, the resistance, and the load. If the resistance is high or the load is great, the voltage will drop. I think this is what is happening, the load and resistance are conspiring to drop the voltage. Specifically, the resistance in the dirty switch contacts is the trouble spot. The load is high by design -- lights are load -- but the load and voltage are constant (the lights and the voltage have not changed) so the remaining variable is the resistance. I've noticed that my back up lights work on occasion (I noticed them on one day when my wife was backing out of the driveway), so there must be a variable that includes environmental conditions -- the resistance is acceptable in some conditions so the lights come on.

I am not aware of any adjustments to the switch, and I have not been motivated to find the switch itself. I suspect that when the switch is removed, you may find a way to shoot it with contact cleaner and revive it. The switch will be located on the transmission.

Reply to
Jeff Strickland

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