Top row. Second from right. Should be shorter than the other top two
Need a pic of tail light wiring 1970 fj40. (7 Viewers)
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- Thread starter
- #23
I'm starting back on the lights next week after being side tracked by a rebuilt steering box, new gas tank, clutch etc. I ended up buying a new turn signal lever assembly and a flasher box to try. I'll add them in one at a time and see what works. I'll let you know.
Coolerman
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The rear wiring on the 69 to 74 FJ40 is very simple:
If the wire is solid green it's the park/side marker/license light.
If the wire is Green/Orange it's the left Turn/Brake
If the wire is Green/Yellow it's the right Turn/Brake
If the wire is Red/blue it's the reverse light
Adding a trailer plug to this year range is simple:
Tap into the Green wire and connect to the BROWN wire on the trailer plug. This is the Tail Lights
Tap into the Green/Orange wire and attach that to the Yellow wire on the trailer plug. This is the Left Turn.
Tap into the Green/Yellow wire and attach that to the Green wire on the trailer plug. This is the Right Turn
The white wire on the vehicle side of the trailer plug MUST attach to the vehicles frame ground!!! Use a tail light mounting bolt for this! A lot of folks leave this off then proceed to hack up the harness thinking something else is wrong.
Back to your issue:
ALL front and rear lights on a 1970 (except the headlights which have their own ground wire) MUST ground to the body through the mounting
bolts, so be sure to clean that area to bare metal.
The most common problem with the early trucks is the turn signal switch connections. These are so easy to get hooked up incorrectly! There are 6 wires coming out of the switch with MALE bullet connectors that connect to 6 harness FEMALE bullet connectors as follows:
Switch Green/Blue to Harness Green/Blue this is the FLASHER signal from the L terminal on the flasher. (Note this also goes to the Hazard Switch)
Switch Green/White to Harness Green/White this is the BRAKE Light signal from the brake switch
Switch Green/Orange SHORT Wire to Harness triple female bullet connector. Note the dash light left turn indicator and the Left Front Turn signal wire also plugs in here
Switch Green/Yellow SHORT Wire to Harness Green/Yellow triple female bullet connector. Note the dash light right turn indicator and the Right Front Turn signal wire also plugs in here
Switch Green/Orange LONG Wire to Harness Green/Orange this is the rear left turn/brake signal
Switch Green/Yellow LONG Wire to Harness Green/Yellow this is the rear right turn/brake signal
If all that is hooked up correctly AND all your lights are grounded properly (don't forget to check the bulb SOCKETS for corrosion!!! A Dremel with a small wire wheel brush makes cleaning the sockets super easy. DISCONNECT THE BATTERY BEFORE DOING THIS!!!) AND all your bulbs are good then the only thing left that can mechanically go wrong is the turn signal switch or the Hazard Switch. Both are easy to take part and clean as mentioned above. The early turn signal switch also suffers from another mechanical issue: It must be mounted and aligned correctly or the lever will not activate the switch all the way. The rod can also seize up in the housing...
If the wire is solid green it's the park/side marker/license light.
If the wire is Green/Orange it's the left Turn/Brake
If the wire is Green/Yellow it's the right Turn/Brake
If the wire is Red/blue it's the reverse light
Adding a trailer plug to this year range is simple:
Tap into the Green wire and connect to the BROWN wire on the trailer plug. This is the Tail Lights
Tap into the Green/Orange wire and attach that to the Yellow wire on the trailer plug. This is the Left Turn.
Tap into the Green/Yellow wire and attach that to the Green wire on the trailer plug. This is the Right Turn
The white wire on the vehicle side of the trailer plug MUST attach to the vehicles frame ground!!! Use a tail light mounting bolt for this! A lot of folks leave this off then proceed to hack up the harness thinking something else is wrong.
Back to your issue:
ALL front and rear lights on a 1970 (except the headlights which have their own ground wire) MUST ground to the body through the mounting
bolts, so be sure to clean that area to bare metal.
The most common problem with the early trucks is the turn signal switch connections. These are so easy to get hooked up incorrectly! There are 6 wires coming out of the switch with MALE bullet connectors that connect to 6 harness FEMALE bullet connectors as follows:
Switch Green/Blue to Harness Green/Blue this is the FLASHER signal from the L terminal on the flasher. (Note this also goes to the Hazard Switch)
Switch Green/White to Harness Green/White this is the BRAKE Light signal from the brake switch
Switch Green/Orange SHORT Wire to Harness triple female bullet connector. Note the dash light left turn indicator and the Left Front Turn signal wire also plugs in here
Switch Green/Yellow SHORT Wire to Harness Green/Yellow triple female bullet connector. Note the dash light right turn indicator and the Right Front Turn signal wire also plugs in here
Switch Green/Orange LONG Wire to Harness Green/Orange this is the rear left turn/brake signal
Switch Green/Yellow LONG Wire to Harness Green/Yellow this is the rear right turn/brake signal
If all that is hooked up correctly AND all your lights are grounded properly (don't forget to check the bulb SOCKETS for corrosion!!! A Dremel with a small wire wheel brush makes cleaning the sockets super easy. DISCONNECT THE BATTERY BEFORE DOING THIS!!!) AND all your bulbs are good then the only thing left that can mechanically go wrong is the turn signal switch or the Hazard Switch. Both are easy to take part and clean as mentioned above. The early turn signal switch also suffers from another mechanical issue: It must be mounted and aligned correctly or the lever will not activate the switch all the way. The rod can also seize up in the housing...
- Thread starter
- #25
You saved me a ton of time. Thanks!
I know this was posted 5 years ago but this helped me out today bigtime. Although my issue turned out to be a nick in the wiring harness that cut the green/yellow wire towards the rear of my 40 causing my left brake light/turnsignal not to work. At least this confirmed all was good with the turn signal wiring and saved me a lot of time. Thanks!
midknightc3
SILVER Star
Resurrecting and old thread, trying to figure out the wiring on my wife's 40. When we apply the brakes all the parking lights come on including all the dash lights. When you turn the parking lights on, the brake lights come on as well (both filaments of the brake light come on either way). Assuming this was a hacked trailer wiring job I crawled under and what a mess...But part of that mess is this thing, anyone have any idea what this is/does/is it in any way factory?
Thanks!
Clark
Thanks!
Clark
midknightc3
SILVER Star
Found the cross wiring problem, PO had put a wire nut (yes, household wire nut) and connected two solid green and two green w/white stripe wires. No clue, but I've fixed that problem. Need some new plugs and thing will be good, but still wondering what's up with the Taiwanese box there.
The box is likely a 3 wire to 2 wire trailer harness conversion device.
Your rear frame member appears to have a rectangular cutout for the rear combination lamps. That implies three way lamps: signal, stop and backup. The box converts the two separate signal and brake wires on each side into one output wire for each side (signal & brake) into the typical 4 wire trailer connector. The 4 wires for the trailer are right stop/signal, left stop/signal, running, and ground back to tow vehicle ground.
The customary combination lamp for small trailers has one filament for both signal and stop for each side.
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midknightc3
SILVER Star
@73FJ40 , the truck does indeed have the rectangular rear taillights, though I have no idea if this is actually original to the truck or if the wiring itself is even original. I'm finding this truck is the real life incarnation of Wayne Kemp's "One Piece at a Time." Thank you for bringing up the trailer converter, I hadn't thought of that angle and was thinking it was something related to the turn signals. If this is a 3 to 2 wire converter, would I be able to get park/running lights AND break out of the same bulb? I'll be reading up on these converts!
Clark
Clark
pb4ugo
SILVER Star
How are your taillights currently setup? In the 2 wire set up 1 wire is stop/turn, the other is for the parking light. With symptoms you describe, I'd 1st check your grounds. Bad grounds can make wierd things happen.
IF your truck is wired for the three way lamps (stop/signal/backup) you could use a 3 to 2 wire converter if you wanted to use combination lamps like the round pre-74 Fj40 ones. They have one bulb with two filaments, one stop/signal, the other parking light.
I wouldn't use that converter box you have, of unknown provenance.
midknightc3
SILVER Star
@pb4ugo I fixed the instigating issue of the brake peddle turning on the running/dash lights, and having the headlight switch pulled out in either position powers the brake lights, with no dimmer function for marker lights. That issue appears to have been related to two separate solid green wires being wire nutted together with a green w/white stripe wire. @73FJ40 the rear frame is cut for the rectangular three bulb housings, the passenger appears wired with a factory non-locking 4 wire plug, the driver being wired with a 6 prong plug that is only using 4 of the prongs. The housings that were installed are aftermarket, so no telling what the true original was. Replacement housings that I want to install from @cruiseroutfit are OEM Toyota with the locking 4 prong NON-waterproof plugs (@ToyotaMatt has a writeup on the various plugs). Without doing appropriate investigation I had simply ordered the OEM housings based upon year, thinking they would just plug in...oh silly me, nothing just plugs in on this truck!
EDIT: I believe the frame matches the vin card, NAS 1974. The tub is an Australian 1975. I think both had the 3 bulb tail lights? There are many other parts from many other years scattered throughout, but I'm guessing which ever truck donated the wiring harness, it was originally wired for the three bulb housing. Sounds like the cleanest course of action would be to chase the wires back until I can find what appears to be factory harness, cut out the poorly installed aftermarket trailer converter, and run new wire back to the tail lights and then do my own clean install of a trailer wire harness.
EDIT: I believe the frame matches the vin card, NAS 1974. The tub is an Australian 1975. I think both had the 3 bulb tail lights? There are many other parts from many other years scattered throughout, but I'm guessing which ever truck donated the wiring harness, it was originally wired for the three bulb housing. Sounds like the cleanest course of action would be to chase the wires back until I can find what appears to be factory harness, cut out the poorly installed aftermarket trailer converter, and run new wire back to the tail lights and then do my own clean install of a trailer wire harness.
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when you have a old , PO , and more PO and then a 4th PO patch-work-smurf-mess like above ....
- unplug at the fire wall and carefully de-plug and work your way back .
- rolling sub harness and taking lots of photos and hand written notes too !
- in the end , you will spend countless hours LESS time and less frustrating time just re-creating the original tail lamps sub harness , it has your back up lamp / switch circuit and gas tank sender too
- fairly straight forward , ADD the white wire w/ black tracer ground circuit to ALL devices , side markers fuel sender via ring terminal etc ...
- LOOSE the ghetto trailer black china box idea too !
- the EWD diagram is your roadmap to set your self up for success here
- TOYOTA never soldered splice points , so DON'T !
- use crimp , heat shrink adhesive lined 3M marine grade BUTT connectors ....
THIS IS THE WAY ....
.
midknightc3
SILVER Star
Making good progress, but slightly confused as to the difference between green w/black stripe and green w/orange stripe, both appear to be left turn signal on the wiring diagrams?
midknightc3
SILVER Star
So Green w/black (GB) has power to the turn signals, but green w/orange (GO) isn't plugged in under the hood. I don't see anywhere to plug the GO in under there. @ToyotaMatt , can I just stick with GB for both the rear turn signal and taped into for the trailer wiring? This leaving the GO unused.
is the Green w/ Oarnge tracer stripe bullet there in photo coming from the rear chassis sub harness section
or
going to it from the engine bay on back along the frame rail ?
- more photos , a overview showing more of what all you have there in front of you is very very helpful here ..?
- i can then better make a suggestion here ...
- i DO see it looks very very crusty a bit , and perhaps this suggests it was always simply never used or plugged into a female bullet , but confirm and verify is the next step by step here ....
,.
..
midknightc3
SILVER Star
That bullet goes into the harness under the hood and is situated with those two plugs on the passenger firewall. It then splits off into three GO somewhere along the way, with all three at the rear frame. I do have continuity between that bullet connector and the three GO wires at the rear, but I do not see any female bullet nor any other GO wire it could have ever plugged into. On the wiring diagram it appears the GB wire at the back was the original factory left turn signal going to the factory trailer plug, GO for the rear left turn lamp, but I'm not sure why there are three GO at the back. I will try to edit this post with some more pictures when I get to work.
Clark
Clark
your Green w/ Oarnge tracer stripe is related to this part below ,
i have not run into this topic in a long long time , it was not until i looked into the EWD for your modle year did i see the ( OPT ) lingo there in the rear chassis harness ...
unless you have this switch at the rear of your truck w/ a round plug type oem Toyota trailer option , it has a spring loaded door to it , then your leave the green w / orange tracer alone and as is , the crusty bullet in engine bay was never plugged into anything , it appears since day 1 new car ..
hope this helps ..
.
midknightc3
SILVER Star
Interesting, this is very helpful indeed! I will continue to ignore those wires then, probably continues to explain some things as some of these were wired in all over the place in random locations between both tail lights, but are obviously not connected to anything. PM inbound re-the plugs themselves.
Thanks all!
Clark
Thanks all!
Clark
