E46 M3 SMG Coupe Reverse Lights not working

[LatinSkllz]

I’ve searched and there’s a lot of different troubleshooting. However, mine is just weird.

I don’t know how long this has been happening as I don’t have a bulb out indicator on dash. Verified the following:

1) Continuity test on both pins for connector, OK
2) Voltage to power wire on each connector, OK
3) new bulbs

What I have found if connect the bulb socket to their respective plug, engage R, I do get a 12V signal on the metal resting pad where the bulb is inserted (makes contact with bulb). This is without bulb inserted. As soon as I insert the bulbs, the 12v drops to 0v.

I did pry up the bulb footer pad to ensure that it makes contact with bulb upon assembly.

I suspect one of the bulb sockets is defective but why would there be voltage supplied without bulbs inserted?

Doesn’t seem like the typical scenarios I’ve searched on.

I would think the side of the bulb is the negative side where as the bottom footer touching the pad is the 12v signal.


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[sapote]

I’ve searched and there’s a lot of different troubleshooting. However, mine is just weird.

Does your tranny have the Reverse switch on the left side? If it has one wire then short it to ground should turn on the lights, and if 2 wires then short them together and should turn on the light.

[Petener]

This might help.. BMW E46 Trunk Wiring Fix! Trunk button/Reverse/Plate Lights NOT WORKING! - YouTube

[LatinSkllz]

Does your tranny have the Reverse switch on the left side? If it has one wire then short it to ground should turn on the lights, and if 2 wires then short them together and should turn on the light.

This fixed it. New reverse switch. Thanks sapote!