Some sort of planetary alignment must be happening, I’ve been talking to a few Vanagon owners about headlight relays, so I thought I’d post a couple of diagrams. Adding headlight relays to the van is a good idea, it redirects headlight power current away from the hi/low beam selector switch and the headlight switch. By passing the switches helps to maintain a good voltage to the lights and most likely prolongs the life of the switches. Also, if upgrading the lights to higher wattage bulbs, then relays are a definite requirement.
First off, here is a diagram I made years ago when I did the mod to my ’82 westy. For some reason I think the diagram has an error in it, can anyone see it? Seems silly to post a schematic that I am not 100% sure of, but on the other hand if one was to study it to find the error one would come away with a better understanding of the headlight circuit 🙂 Oh, one more thing, if I was to do this over, I’d run separate fused power for each relay.
Note: Mark Drillock pointed out that: “For the early diagram there are a couple things I would change. The red wires to the headlight switch and hi/lo switch are both labeled as coming from fuse S9. This is not really true and misleads people into thinking those 2 wires are fuse protected. They merely connect to the back of the fuse holder on the end that the fuse itself gets power from sharing that power source. The fuse does nothing for those red wires.”
He also notes: “Also your added note in the later diagram about the red wire to term 30 of the hi/lo switch applies as well to the earlier wiring.”
Thanks for the clarifications Mark, I’ll look for the original source file of this diagram and change it.
Edit: well I couldn’t find the original file so I dashed off a new version, quick and dirty.
And now on to the post ’85 Vanagon wiring. A couple of notes first. The power source for the relays can be the “P” terminals on the left side of the fuse panel if looking from the front, or the right side of the panel if looking from the rear, ha!
Or you can run new wires directly from the battery. Whatever source you decide to use, you HAVE TO install inline fuses close the power tap. The relays themselves can be clipped onto the top of the fuse panel if you have a couple of those relay bases that fit. This diagram does not include upgrading the wires from the panel to the lights, but does retain the stock fuses for each beam/light. I have gone over the diagram, I believe it to be accurate, please post any corrections in the comments.
There are suppliers that will sell you a kit to do all this, a good one is sold by Jay Brown.