I have an electrical problem. I have a 99 1 ton that is a rebuilder it had a cab fire. I replaced all engine and fender looms, I got a different cab with a different dash. I put it all together and everthing works except the head lights. I turn the lights on and both headlights come on, but when I click on high beams the headlights go real dim almost out so do running lights my mechanic checked the grounds and says there good. He cant seem to find the problem, so i am looking for some ideas. Thanks pat