Brake light illuminating instead of turn signal

[cumblechook22]

Greetings, everyone.

I am now addressing yet another issue with my 2003 Z4 2.5L E85, but progress is being made.


When I signal left, everything functions correctly; however, when I signal right, the ticking noise accelerates, and the rear brake light flashes instead of the indicator. How bizarre! When I activate the hazard lights, they operate as anticipated. I believe all bulbs are functional, with the exception of the side repeater, which I have not checked for replacement; nonetheless, I do not anticipate it being defective.

I established a temporary ground connection to the light cluster at the rear, as the faulty ground at the cluster was a convenient starting place; nonetheless, it yielded no improvement. Any guidance would be greatly appreciated. I have encountered mentions of 'rear tail light earth' in many threads here, but I have been unable to locate any specific information

[ML350_Colin]

Can the bulb holder from the opposite side be temporarily fitted to determine if the defect transfers sides?

[cumblechook22]

That is a compelling concept. I suppose there is no harm in attempting.

[Screwdriver_1]

Initially, I considered the earth connections; nevertheless, after thoroughly reading the entire post, I recognise that you have already attempted it! 😊

[Darrellll]

What specific Earth fix did you implement?It appears like the back earth pin or wire has been burned or is burnt out.

[cumblechook22]

I disconnected the ground tracks in the light cluster and connected a line directly from the battery, thus the ground should be adequate.

[IrvesBMW]

Faulty bulb or grounding issue.
Exchange the bulbs laterally to evaluate that component.

[cumblechook22]

There is no evidence of combustion or thermal damage around the cluster connection or the terminal connector of the wire. Are there further earth connection points to verify, and if so, what are their locations?

[cumblechook22]

I have successfully resolved it! The block connector connections on the aesthetically pleasing, although subpar quality, aftermarket headlamp components had begun to deteriorate. Several tips of the pins were really disintegrating. I connected the block and, after identifying several faulty lights, discovered that everything began functioning properly. The extensive hours of meticulous re-wiring yielded commendable results, undoubtedly! Aside from the expense of a batch of Scotch connectors, it was complimentary (quite atypical for my Z4)! Joyful days!

[cumblechook22]

🫠