Fj40 wiring disaster for taillights

[Cruiserookie]

Hello everyone. I recently redid my wiring on my 76-78 fj40. I used ez wiring. A buddy of mine did it for me and got to the taillights and basically gave up.
Did research and found out it was the hazard switch that screwed everything up. Got a mechanic to finish it up and he’s wondering if there is something out there that plugs into the existing hazard wiring harness....

Basically the other end of this attaching to the ez wiring harness...
Any help would be appreciated.

 

[edwjmcgrath]

For short $ Coolerman sent me a color correct rear harness that was plug and play. No surprises and no electrical tape.

 

[Coolerman]

Unfortunately, since you used a none OEM main wiring harness, I cannot provide a rear chassis harness that would do you any good...

That being said, your mechanic was able to get it all working? Hazards, turn and brake lights? If so, he is pretty good!

There is nothing out there that will allow an OEM Hazard switch to "plug into" any aftermarket harness. These aftermarket harness are designed for Chevy engine/steering column/turn/stop lights based hot rods, not FJ40 Land Cruisers. It was not the Hazard switch that messed everything up, it is the fact that the later (after 9/1973) FJ40 uses a separate bulb for the turn/Hazard lights, unlike the combined bulbs most US vehicle use for the Stop/Turn function.

You, the end user, (or your mechanic) have to figure out how to interface the OEM switches to the Chevy harness. This usually involves cutting the connector off an old OEM FJ40 harness that matches the Hazard switch, looking at the schematic for your year FJ40, then duplicating part of the OEM Hazard wiring to allow mating with the Chevy harness. Painless actually has a manual you can download showing how to do this for SOME, but not all years of the FJ40.

 

[Cruiserookie]

Thanks for the reply.
What does OEM stand for?
No, my mechanic didn’t get the lights to work unfortunately. That’s where we are stuck.
I will look into the painless manual and hopefully it’s got the year of my FJ. Although I’m not sure exactly what year it is... it’s got to be between 76 to 79 I’m thinking. It still has drum brakes on 4 tires and the gas tank under the passenger seat.
So what should I have done instead? My wiring was a disaster when I got the thing. When I called ez wiring they said oh ya everyone gets this for the FJ40 it will work no problem. Well she obviously lied. Lol
Thanks for your help.

 

[Jdc1]

Thanks for the reply.
What does OEM stand for?
No, my mechanic didn’t get the lights to work unfortunately. That’s where we are stuck.
I will look into the painless manual and hopefully it’s got the year of my FJ. Although I’m not sure exactly what year it is... it’s got to be between 76 to 79 I’m thinking. It still has drum brakes on 4 tires and the gas tank under the passenger seat.
So what should I have done instead? My wiring was a disaster when I got the thing. When I called ez wiring they said oh ya everyone gets this for the FJ40 it will work no problem. Well she obviously lied. Lol
Thanks for your help.

There are a few threads that deal with this issue.

1978 turn/hazard wiring schematic

forum.ih8mud.com

You’ve got to recreate the brake/hazard/turn circuit.
You definitely want to find out what year your truck is. I’m guessing that if it’s a 76-79 with drums at all 4 wheels, it’s a South American spec.

 

[Living in the Past]

Thanks for the reply.
What does OEM stand for?
No, my mechanic didn’t get the lights to work unfortunately. That’s where we are stuck.
I will look into the painless manual and hopefully it’s got the year of my FJ. Although I’m not sure exactly what year it is... it’s got to be between 76 to 79 I’m thinking. It still has drum brakes on 4 tires and the gas tank under the passenger seat.
So what should I have done instead? My wiring was a disaster when I got the thing. When I called ez wiring they said oh ya everyone gets this for the FJ40 it will work no problem. Well she obviously lied. Lol
Thanks for your help.

O original
E equipment
M manufacturer

 

[Coolerman]

In your case your "year" will be what year the electrical dash switches are. That will determine how to wire the Hazard and turn switches.
To see what year your Hazard switch is go here: FJ40 Hazard Switch ID

Your switch is a 9/72 to 8/1977 switch

 

[ryanwk628]

I will look into the painless manual and hopefully it’s got the year of my FJ.

If you find this can you post a link to it? Interested for reference

 

[Coolerman]

You can download it from my web site here: Painless FJ40 Manual

Once you click the link it will pull up a LONG list of schematics, manual and other documents. Scroll down past the 1983 FJ40 schematic until you see the Radio section. The painless manual is right under that. Click on that and it will ask where on your computer you want to download the PDF document to. The last couple of pages of the pdf file show the FJ40 switches and how to wire them.

 

[gericurl]

I've got the same issue with a painless harness. P.O. had totally bypassed the hazard switch. I had all my switches/cables/knobs redone by @RAGINGMATT (They came back AMAZING!) and dug into the wiring to get everything working. I still haven't cracked the hazard switch.
I even redrew the entire wiring diagrams of both the Painless diagram and the Haynes manual diagram in Illustrator so I can turn off the visibility of sections to just see the circuit I am working on (MUCH less visual clutter than trying to trace through an entire harness diagram). I've physically traced every wire from end to end and redid all of the P.O.s connections (he had a weak forearm or a Harbor Freight crimper). What I found was that the diagrams don't necessarily show the right wire color from the OEM switches (at least for a '74) That, combined with the mess of the painless harness rat's nest of colors that don't match OEM, it is pretty confusing even going wire by wire.

With the experience I have under the dash, I'm now confident I can build my own (more OEM) harness using stuff from @Coolerman (who's expertise/website is solely responsible for all the wiring success I've had to this point). I've just spent every free moment of the last year on my truck, so for my sanity and my marriage, I need a break for a few months at least. Then I think I'll dig in to drawing my own diagram that includes all the USB and power ports, relays etc... to my Tuffy Console, shift knob buttons, and trailer light plug, off-road lights and any other planned goodies that I don't have yet.

My shift knob is a flight control stick from an A-10 Warthog. I have disassembled it and re-soldered wires to the contacts of each button and bench tested them. I intend to make the 2-stage trigger honk my horn on short pull and honk the horn/power every light on the truck on full pull. I haven't assigned the rest of the buttons specific jobs yet, but I have a bunch of ideas swirling around in my head.

 

[Coolerman]

Damn, that was a lot of work to draw that! It looks fantastic! If you were willing to send me a full size file I would be happy to add that to the schematics page!

Also love your idea of a single button to sound the horn and light up the truck when some damn soccer mom pulls out in front of you. On my ride into work this morning (rode my motorcycle) I had a lady in a Lexus SUV pull out in front of me on a two lane country road. I was doing 55mph and would be dead if there had been on coming traffic. I was able to swerve around her. She can't claim to have not seen me either as I run dual forward facing 10W LED spot lights that flash. They are VERY bright. (I have had many people pull over thinking I am a motorcycle cop when I have them on. My bike DOES look like a cops motorcycle as it's white and gray and I wear a white helmet, gray riding jacket, and black engineer boots!)

 

[Toyo_Judson]

I've got the same issue with a painless harness. P.O. had totally bypassed the hazard switch. I had all my switches/cables/knobs redone by @RAGINGMATT (They came back AMAZING!) and dug into the wiring to get everything working. I still haven't cracked the hazard switch.
I even redrew the entire wiring diagrams of both the Painless diagram and the Haynes manual diagram in Illustrator so I can turn off the visibility of sections to just see the circuit I am working on (MUCH less visual clutter than trying to trace through an entire harness diagram). I've physically traced every wire from end to end and redid all of the P.O.s connections (he had a weak forearm or a Harbor Freight crimper). What I found was that the diagrams don't necessarily show the right wire color from the OEM switches (at least for a '74) That, combined with the mess of the painless harness rat's nest of colors that don't match OEM, it is pretty confusing even going wire by wire.

With the experience I have under the dash, I'm now confident I can build my own (more OEM) harness using stuff from @Coolerman (who's expertise/website is solely responsible for all the wiring success I've had to this point). I've just spent every free moment of the last year on my truck, so for my sanity and my marriage, I need a break for a few months at least. Then I think I'll dig in to drawing my own diagram that includes all the USB and power ports, relays etc... to my Tuffy Console, shift knob buttons, and trailer light plug, off-road lights and any other planned goodies that I don't have yet.

My shift knob is a flight control stick from an A-10 Warthog. I have disassembled it and re-soldered wires to the contacts of each button and bench tested them. I intend to make the 2-stage trigger honk my horn on short pull and honk the horn/power every light on the truck on full pull. I haven't assigned the rest of the buttons specific jobs yet, but I have a bunch of ideas swirling around in my head.
View attachment 2081534

This is AWESOME!!!

 

[Cruiserookie]

Thanks for all the feedback. I will print all this info off and take it to the guy that’s working on my cruiser. Hopefully this won’t scare him off. This is the third guy I have taken my cruiser too. Haven’t driven it in about 3 months and summer is almost gone. Totallly sucks.

 

[gericurl]

Damn, that was a lot of work to draw that! It looks fantastic! If you were willing to send me a full size file I would be happy to add that to the schematics page!

I'm only hesitant to send it "as is" because it was drawn (really it was copied with the colors added to the wires) with my specific truck in mind. I did not include anything that I was not wiring (smog stuff for example). Also my designer OCD would have me polish it a bit before "publishing". It was good enough for my own personal tool/reference, but I would be mortified to send it out as is.

Plan: I'll tidy it up and get you the more universal version with all the circuits included. I am wanting to add a trailer socket anyway and sort out my Hazard switch. I would feel better if you gave it the once over as well, second set of eyes is always welcomed.

I'm also thinking it would be cool to make a multi-page reference .pdf out of it. So if you are having trouble with say... your ignition switch. I would have the whole schematic at the first page, but you could navigate to a page in the .pdf that has all the circuits hidden except stuff that is directly tied to the ignition switch. It's a lot of work, yes, but (re)drawing it helped me a TON to understand the wiring in my truck and automotive circuits in general. My ability to diagnose and fix gremlins is by no means "advanced" but I'm miles ahead of where I was 3 months ago, and would describe myself as "comfortable" noodling in the harness.

I would be honored to have the diagram included in the legend that is your website. I'll get to work on it. If you have any other drawings that you need, reach out and I'll see what I can do.

Also love your idea of a single button to sound the horn and light up the truck when some damn soccer mom pulls out in front of you...

EXACTLY my thoughts. I've worked on creative for Motorcycle safety campaigns for both Utah including these billboards:
UHS Motorcycle billboards and just wrapped up some work for Colorado's motorcycle campaigns.

Glad you are good, it's no joke out there for motorcycles.

 

[Cruiserookie]

You can download it from my web site here: Painless FJ40 Manual

Once you click the link it will pull up a LONG list of schematics, manual and other documents. Scroll down past the 1983 FJ40 schematic until you see the Radio section. The painless manual is right under that. Click on that and it will ask where on your computer you want to download the PDF document to. The last couple of pages of the pdf file show the FJ40 switches and how to wire them.

So just to be clear I got the EZ wiring harness kit. Is it technically the same as the painless wiring kit?
What are the other options for a whole rewiring of an FJ 40 if you don't use either of these kits?
thanks again