"2001 BMW E46 Left Rear Turn Signal Problems"

2001 Silver BMW E46 Right Side View

My 2001 BMW E46 left rear turn signal went form normal, to the speedy mode, and now is dead. The mechanic says it is $170.00 for the taillight holder and wiring work. He said he thought there was evidence on the wires of a problem.I could find no obvious prob with the wiring. I put a a working bulb in and that didn’t work. I moved the holder from the right side over and the turn signal didn’t work, but a different one of the three bulbs, either the brake or reverse, lit up and stayed on. The ignition and lights were off. That oddity really confused me. I do not have the fuse diagram, apparently it is not in the manual or anywhere I can find it near the fuse box. But, I have to assume my mechanic tried that anyway. I am going to buy the replacement left rear holder, but if that does not work I am at the end of my rope. Any ideas?

Answer: If the bulb carrier (taillight holder as per your description) is bad/burnt/corroded/kaput then it has to be replaced. But in addition, the cable connector to the carrier should be checked for burnt or loose pins/sockets. If so then the connector should also be replaced.
Finally, additional grounding should be provided to the carrier. Using the original ground cable (colored brown), somehow splice in an additional wire and connect to the reserve ground terminal in the carrier.
If you desire, the additional grounding should also be done to the other side. Otherwise what happened to the left will happen to the right side too.

2001 BMW E46 Left Rear Turn Signal