Guys I'm having an headlight issue, all.

Hi guys I'm having an headlight issue, all lights come on at once low beam high beam an all park lights when light switch is in auto, but all lights on the driver side are dim, I try to use the switch manually and when I put the switch in the park lights only, they work like they suppose to but as soon as I turn the switch to all the way on all the lights come on again low beam high beam an all the park lights, but like I said the driver side is dim. I've changed all the harnesses leading to the headlight assembly and I've changed the headlight switch, all fuses an relays are good but still same issue I'm lost guys so thanks in advance for ur help. James