[ This is a 99 quad cab. The driver side headlamp is very dim. I tried a new bulb and took the battery out to check the the grounds and in the process cleaned the battery acid from the area. Any suggestions would be greatly appreciated. By the way the passenger side lamp works great and the high beam bulb works great too. Thanks again.

 

Check the body grounds, It sounds like a ground issue

 

Do you think this is the case with only one bulb going dim. The high beams both work great. Any other suggestions.

 

check your grounds , if not , do a voltage drop test across the load. (light)

 

If I turn the high beams on they will not turn off unless I turn the lights off at the switch on the dash. When I turn the lights back on the high beams are off and the drive side light is very dim. Could this be part of the switch in the colum?