I’d really appreciate some help with my Audi A4 B5 from ‘98. I have a problem with my rear lights. I took the car for an MOT and it failed because the rear lights go out whenever the headlights are switched to main beam. I hadn't noticed this during the summer because I never used main beam!
The rear lights work just fine on sidelights or normal headlights, the problem only occurs when main beam is activated.
I should mention that I have aftermarket headlights on the car (Devil Eyes by Dayline) and that on the left side the LED strip stopped working during the summer (not sure if that is related or not). I replaced the headlights because I needed to change to LHD pattern ones having moved to Finland. I did try to get standard headlights twice but both places delivered the wrong headlights so I kind of ended up with the Devil Eyes because they were available (getting parts here can be difficult). I no longer have the old headlights or I would be able to swap back to them as a test.
Could the headlights be causing this problem with the back lights? Has anyone experienced a similar problem before?
Any help would be appreciated, I need to retest the car in a couple of weeks and nobody locally seems to be able to help me.