Headlight rewiring guide (headlight relay plug melting)

[lucasschwartz]

In reading the threads, it seems the headlight relays are a common point of failure, with melted wires and fuse box plugs. (Discovered this after the wires into my own relay heated to smoking hot)

Id like to create a resource guide to wire in aftermarket relays and harness/wiring blocks.

i have a couple questions to get started.

I haven't been able to source a wiring diagram. Does anyone know the color codes of the high beam and low beam control wires?

[terrence]

Here is the wiring diagram, headlights towards the bottom:

http://toyotavans.org/community/tips/manual/028_ELECTICALWIRINGDIAGRAMS.PDF

[lucasschwartz]

Many thanks Terrence! and thanks for the patience- van life has been on hold as I moved everything I own from Oakland back to Portland! And damn it feels good to be home again!

I took apart the dashboard today and dove into it- but I think I'm missing something about the way these 3 prong relays work. Does anyone grasp how the red-white wire is modulating the high beams?

I tried it a couple different ways (connecting the red wire to the red-white wire directly to then use the red-yellow and red-green wires as signal wires for the new relays.... but smoke started coming up from the steering column almost immediately... so... don't do that, fellas.)

Presently, I wired in a new switch between the red power wire and the red-black power to the headlights. This gives me low beams, but no way to switch on the high beams. Does anyone have a firm grasp on how to use the current headlight switch to actuate new relays?

[boogieman]

i recently picked up an '87 that had fuse box issues, both a burned heater motor lead and headlight relay/fuses....the previous owner had a shop rewire a relay and two fuses for the headlights. it looks correct but the problem is i get all 4 lights on for low beam and the outside ones change for high beams....i tried another combo switch and same result...not sure what im missing, 5567

[boogieman]

5572

well thats annoying, why is it always the last place you look? after ripping apart the fusebox and dash and checking the switch 3 times i was gonna disconnect the highbeams until i could figure it out...

i guess this was some sort of fix before the headlight relay/fuses were corrected...?

[podunkvariant]

Boogieman I know its been years but did you ever figure out why all 4 lights were on for low beam and outside one changing for high beam? I am having the same issue and I also noticed someone had rewired the headlight relay. Interested to know what the problem was. Thanks.

I have a 1987 Master Ace Surf.

[boogieman]

they added that ground in the second pic..maybe it was done before the fuses had been rewired to make them work period but im not sure...when i undid the ground all was back to normal

[podunkvariant]

Thanks boogieman. I appreciate your response. Glad you figured it out.