on a jeep cherokee 2000
right headlight works fine, daytime running light, low beam and hi beam.
left headlight (drivers side) has no more daytime, very weak low beam and no hi beam.
checked and clean connectors, replaced left head light, no difference, same problem.
unplugged daytime module, made no difference except killing daytime on right side.
any ideas?

 

I found something on that, maybe this will help? https://www.cherokeeforum.com/f2/headlight-woes-62973/

 

already removed grill and header panel to check wiring and wiggled with it...no difference. will check fuses next

 

Did you only check the wiring at the connector. You did trace all the wiring and clean the grounds too. That issue resembles a grounding issue