LV Wiring...Help!

[peterman]

I'm just finishing rewiring my LV. Traced and replaced things one by one. Don't have a wiring diagram, but have used deductive logic and a 40 diagram from the Haynes manuel. Everything works great except the tail lights. I had the running and brake lights into one lead of the 1157 and the turns into the other. Night differential between running and brake was not enough. So now I'm looking at it and I have left turn (GO), right turn (GY), running (G), and brake (GW) coming off the rear harness and two leads (GY) and (G) from the tail light housing. I can't figure out how to wire the brake into the turn filament without bleeding to the other side. I could give up and do a 5 to 4 wire diode converter, but that's not original. Every time I've run into this sort of thing with the LV, there is some creative Toyota magic that keeps it simple. I'm guessing it's up at the dash in the signal circuit, but that doesn't explain the 5 wire (4 actually since the truck is ground) at the back of my harness. Again, I'm just copying the old machine. I know this is a stupid question but I'm stumped. Thanks!

 

[fogblanket]

Not sure if i can help in that when i wired my l. I atarted from scratch i did have to wire in a trailer signal splitter for the tail. Brake lights
Not sure how the stock system is set up but you will need to make sure that relay is functioning

 

[peterman]

A splitter sounds like the solution unless someone else knows better. Thanks for the reply.

 

[Gumby]

Running goes to one side of the 1157, brake to the other. Turn signal on mine runs through the brake light. There is no separate brake wire that runs all the way back. At least in 64 that's how they did it. The brake light filament on the 1157 is noticeably thicker than the running light one.

From a bad 40 diagram


GW comes from the brake light switch to the turn signal switch. That sends power to both turn signal wires when the switch is in the middle position and power to the non flashing light when the brake is applied.
GR gets power from the fuse and goes to the flasher unit.
GL is power from the flasher to the TS switch.
GY and GO are power from the switch to the lights.
GW to the rear harness is for the trailer brake light optional harness

I think this is how it works. It's early and I'm going from the Haynes

 

[peterman]

Gumby - thank you! I disconnected the GW wire in the back and everything works perfectly. The brakes worked all along through the column turn circuit as you described. That extra GW wire in the harness threw me off. An aux trailer wire would never have occurred to me. And, the truck continues to be pure cruiser with no 5/4 adapter! Thanks again.