If your headlight switch is as bad as the one shown in my tutorial, you will lose voltage and amperage and the output you get will be intermittent at first and finally just lousy...and it doesn't matter how good your wiring is nor how good your ground connection is. This much junk works as resistance. What happens is the contactor bumps wear troughs in the fiberglass or garolite board, the stuff they tear up mixes with the grease used when the switch was built and it makes a non-conductive paste that stays right where it is. It is just that simple and a check with a handheld meter will show it quickly. You must get the contactor and the switch's plate as clean as brand new and if you do, you may be very pleased at the difference in your lights. Please take a look at the images below (taken from the article I wrote) and you'll see why. Good luck!
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
