taillight problems
If that's the case, does this happen when you have the lights on and the hazards?
VANSUVNEW PRODUCTS JCW Shop > "alternating flasher" > AUXILIARY LIGHT FLASHER CONVERSION KIT AUXILIARY LIGHT FLASHER CONVERSION KIT
Permanently converts grille, bumper warning lights into alternating flashers. Includes flasher, bracket, wiring, switch, hardware and instructions. For 12V systems.
I thought that one of these systems might have been installed on the car for some reason. If so, it would solve your problem.

