Tail light wiring (1 Viewer)

[sk8salomon]

I'm replacing the tail lights on my brother-n-law's '75 FJ40. He said the turn signals never worked so when I removed the old light assy, the turn signal wire was not connected. I traced the wires back to the factory harness located rear right hand frame and found a PO must have hacked into it. There were quite a few factory wires left bare. Here's a color list of what I found.

Green w Red stripe
Green w Yellow stripe
Green w Black stripe
Green w White stripe
Green w Black dashed
Red w Blue stripe

Two questions: 1- where can I find out the info for the above wires w/o having to spend $$$ on FSM or Haynes manual. 2- can I purchase the mating factory plug that will snap into the new tail light assy plug?
Thanks.

 

[sk8salomon]

Some pics...

 

[georgia fj40]

Coolerman's Electrical Schematics and FSM File Retrieval

 

[78fj40mg]

@Coolerman sells all the OEM electrical plugs.

Here's the web site Cruiser Wiring

 

[georgia fj40]

or try here. '75 fsm download The Great Cruiser Parts Link Thread

 

[sk8salomon]

Thx, I'll check it out.

 

[GHalll]

Test light helped me a lot..

 

[Solace in Solitude]

^^X2^^. Test light makes it easy... All your green with various stripes make it sound like it's not OEM... But, I have a '78... Maybe it's different colors.

Here's what I know from my '78

Edit: Green Tail lights

Green w Red stripe
Green w Yellow stripe. Right turn signal.

Green w Blue strip. Left turn signal

Green w Black stripe
Green w White stripe. Brake lights
Green w Black dashed
Red w Blue stripe. Backup lights

White w black stripe. Ground

 

[Coolerman]

I have never seen a Green/Red OEM wire in the rear chassis harness for any year. GR is usually the brake switch power feed in the main harness and for the horn power feed.

A 1975 should have these colors for the rear chassis harness:

Green = Tail/Marker
Green/Black = Left Turn
Green/Yellow = Right Turn
Green/White = Brake Lights
Red/Blue = Reverse lights
White/Black = Ground (may not be on an early 1975)

If you have the trailer socket wiring plugs (two, two pin plugs between the rear lights) then you may also have the Green/Blue wire

I do sell those 4 pin connectors both male and female, and the terminals that go with them.

 

[sk8salomon]

Sorry, it's a Dec '74. I went under the truck for a 2nd look and I think the GR is actually GreenOrange. So per the FSM, it looks like that's for the trailer harness which is gone anyways.

 

[sk8salomon]

Got rear tail light re-wired. Good news is that brake lights & tail lights work properly now. Bad news is turn signals & reverse lights not working yet. I crawled under the trans looking for reverse switch wires and found a mess of unplugged wires. First, coming from the top of the trans are two wires, red w blue stripe. In the frame harness on passenger side are 4 wires, red w blue stripe, blue w red stripe, black w yellow and solid red. Any idea what these are?

 

[sk8salomon]

Another thing I can't understand. Cooler mans link to the Haynes manual seem to be correct. Why is this Toyota FSM so wrong? It has (3) FJ55s and (1) FJ40 (L) that doesn't match the Haynes? Wtf?

Pic below is the correct reverse switch indicator showing RL for red w light purple which I mistook for blue

 

[sk8salomon]

The FSM shows a totally different backup switch circuit w LR (Light purple w red stripe) item 45

 

[yayo]

did you ever figure out the reverse switch wiring ?

 

[Coolerman]

The reverse switch will have two RL wires with MALE bullet connectors. The rear chassis harness will have a LR and a RL wire with FEMALE bullet connectors. You would connect one of the RL wires from the reverse switch to the LR wire on the rear chassis harness. This LR wire will have +12V on it when the key is on. Connect the other RL from the reverse switch wire to the RL wire on the harness. Now when the trans is in reverse, the switch will close, putting +12V on the RL wire going back to the reverse lights.

The R and BY wires in the harness are for the 4th gear indicator. These would connect to wires coming from the trans if it is so equipped.

 

[yayo]

thank you @Coolerman

 

[wngrog]

Digging up this old thread.......

I want to put a 4 blade trailer light into my harness.

there are 4 wires. Brown goes to the Cruiser solid green. Yellow to left blinker. Green to right blinker wire. White to ground.

How do the brake lights work?

 

[jimep]

Digging up this old thread.......

I want to put a 4 blade trailer light into my harness.

there are 4 wires. Brown goes to the Cruiser solid green. Yellow to left blinker. Green to right blinker wire. White to ground.

How do the brake lights work?

You need a converter, something like this...

Hopkins Tail Light Converter Kit with 4-Way Flat Connector - LED Compatible Hopkins Wiring HM48895

 

[Coolerman]

If your FJ40 is pre 9/73 you do not need the converter. Connect as follows

FJ40 wiring----- Trailer wiring
FJ40 Green to Trailer Brown
FJ40 Green/Orange or Green/Black to Trailer Yellow
FJ40 Green/Yellow to Trailer Green
Trailer White to FJ40 frame ground

If post 9/73 then a converter is required.

I would highly recommend the Curt 56146 Powered Converter. It does require connection to the battery of the FJ40, but isolates the vehicles wiring from the trailer preventing blown fuses if the trailer developes a short. Because it is powered, the trailer lights will be MUCH brighter than a non-powered converter that uses diodes.

 

[Coolerman]

Digging up this old thread.......

How do the brake lights work?

By pressing the brake pedal, thereby engaging the brake light switch that supplies power to the brake lights? Sorry, couldn't resist!

If your FJ40 is pre 9/73, the brake light signal is magically combined with the turn signal inside the turn signal switch so that one element of the dual element tail light bulb can serve both functions.

If your truck is post 9/73 then the brake light signal is separate from the turn signal and goes to the separate bulb in the three bulb housing.

This is why a converter is needed in post 9/73 FJ40's It combines the two signals so that the trailer single bulb can perform both functions.