I have an 04 Chevy Venture. I purchased it with a melted turn sighnals on the front. I just replace the wiring harness and whole assembly but the blinker bulbs brighten when the headlights are on and dims when the headlights are on? What could cause this issue?

 

Is your problem only at idle speeds, or all the time?

 

Daylight running lights on?

 

Check your battery, battery cables and alternator.