Guys,
There are a number of good headlight relay conversion threads on the board. Here are a few of them:
http://67-72chevytrucks.com/vboard/s...elay+headlight
http://67-72chevytrucks.com/vboard/s...elay+headlight
http://67-72chevytrucks.com/vboard/s...ight=headlight
I am going to add one more based on my recent experience. My headlight switch failed after I installed halogen bulbs in the truck so it was time to go to relays.
I started with a heavy duty headlight harness from LMC Truck #36-3580 ($30). It includes the relays and new headlight lamp connectors. It also has power wire connectors and plug in connectors to the relays. The connector that is supposed to hook to the stock truck wiring is not correct for our trucks and is of no use.
I cut the harness apart and reworked it as shown below. It is a good starting point.
Works like a champ. My next step is to convert from sealed beam to H4 bulbs in Hella E-Code Reflector lamps as explained by Rogue in this thread.
http://67-72chevytrucks.com/vboard/s...d.php?t=395480
TR