Tail & Rear Running Lights FJ60 Not Working
- Thread starter R87FJ60
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Huh...well, I'll bet the MUD community would benefit greatly if you posted up images (scanned or photos) of the updated circuit diagram/info on the relay locations/troubleshooting once you solve this problem...
...or if you really want to be a MUD hero, upload the scanned Supplement in it's entirely in .pdf format here (maybe talk to @Trollhole or a Moderator to get it add to this link):
https://forum.ih8mud.com/threads/fsms.743084/
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Or you could explain any/if any modifications have been done to the truck...Is it stock?
- Thread starter
- #24
Morning Mud.
@Slow Left. I'll take the photo and post the diagrams this am. I don't mind getting the supplement scanned into pdf but it might not be today. I'll have to see how backed up the local print shop is. I will also have to figure how to post that and i might be better at auto wiring than computer tricks.
@rifleshooter. The tail light wiring harness is stock and mostly unmodified.
@Slow Left. I'll take the photo and post the diagrams this am. I don't mind getting the supplement scanned into pdf but it might not be today. I'll have to see how backed up the local print shop is. I will also have to figure how to post that and i might be better at auto wiring than computer tricks.
@rifleshooter. The tail light wiring harness is stock and mostly unmodified.
Nice.
That Trollhole site that has links to almost all the other FSMs (notice that that Supplement isn't there) might be the place to put it...but not sure how that works...that's why I tagged Trollhole, but it might need a MUD Moderator to make the change...once again, not sure how that all works.
Anyways, in that Supplement, it should show the location of the Tail Light relay...and have a procedure for testing it...but if it is the same relay as in the earlier 60s, then you can use the test procedure I posted up earlier (from the 1980 Body Chassis FSM)...
That Trollhole site that has links to almost all the other FSMs (notice that that Supplement isn't there) might be the place to put it...but not sure how that works...that's why I tagged Trollhole, but it might need a MUD Moderator to make the change...once again, not sure how that all works.
Anyways, in that Supplement, it should show the location of the Tail Light relay...and have a procedure for testing it...but if it is the same relay as in the earlier 60s, then you can use the test procedure I posted up earlier (from the 1980 Body Chassis FSM)...
- Thread starter
- #26
I'll work on getting the entire manual scanned to pdf and posted as soon as possible.
Cool. And in the Body Electrical chapter, does it show location of relays, what types of relays and procedures/directions for testing relays?
I be interested in seeing if the relays in the 4/85 on USA FJ60s are different (in number, application or location) than the info I posted in an earlier thread from the 1980 Chassis Body FSM...
I be interested in seeing if the relays in the 4/85 on USA FJ60s are different (in number, application or location) than the info I posted in an earlier thread from the 1980 Chassis Body FSM...
Alright, here's the deal...
When you turn the light switch one click, that should turn on the Tail Lights (aka running lights) but not the headlights.
When you turn the light switch two clicks, that should turn on both the Tail Lights and the Headlights.
So, when the light switch is turned on (either one or two clicks), a path for current to flow is completed (switch closes, circuit completed).
That path originates at the battery + terminal, passes through the middle fusible link and then passes through the Tail Light Relay before grounding through the light switch.
As the current passes through the Tail Light Relay, it closes another switch (that is what a relay does) by generating an electromagnetic field (induction) and literally pulling that second switch closed through a magnetic field.
If you look up on the wiring diagram at the schematic for the Tail Light Relay, you will see inside the Tail Light Relay a pig tail like line (along the path from the battery to the light switch that I outlined above)...that pig tail like symbol is a symbol for an 'inductor'...as current passes through it, it generates an electromagentic field and pulls the switch to it's left (still inside the Tail Light Relay) closed.
When that second switch closes, it allows current to flow now through the 15A Tail Light fuse, then on to all the light bulbs in the dash, and onto all the Tail/License plate lights/side markers and finally into the Headlight Cleaner Relay.
If you measure 12V+ on the far side (away from the battery) of that middle fusible link, then that fusible link is still good.
If you measure 0V with the light switch off and 12V with the light switch on (both one and two clicks) at the battery side of the Tail Light fuse, then the Tail Light Relay is good (or follow the procedure in the FSM to pull and test the relay).
If the Tail Light Relay checks out good, then if you measure 12V with the light switch on (both one and two clicks) at the far side (away from the batter) of the Tail Light fuse, then the Tail Light fuse is good (or pull and visually inspect and measure resistance across the removed fuse).
If both the Tail Light Relay and Fuse check out good, then if you measure 12V with the light switch on (both one and two clicks) at the tail light(s) socket(s) then the wire from the fuse box to the tail light is conducting properly.
With the light switch off, if you measure on the order of tens of Ohms (but not infitinity) resistance/continuity between the ground at the Tail Light(s) socket(s) and ground, then the ground wire is good.
If you pull and test the Tail Light bulbs for resistance/continuity and they read on the order of tens of Ohms (but not infinity) then they are conducting properly (there is continuity...ie. a path for conductance).
When you turn the light switch one click, that should turn on the Tail Lights (aka running lights) but not the headlights.
When you turn the light switch two clicks, that should turn on both the Tail Lights and the Headlights.
So, when the light switch is turned on (either one or two clicks), a path for current to flow is completed (switch closes, circuit completed).
That path originates at the battery + terminal, passes through the middle fusible link and then passes through the Tail Light Relay before grounding through the light switch.
As the current passes through the Tail Light Relay, it closes another switch (that is what a relay does) by generating an electromagnetic field (induction) and literally pulling that second switch closed through a magnetic field.
If you look up on the wiring diagram at the schematic for the Tail Light Relay, you will see inside the Tail Light Relay a pig tail like line (along the path from the battery to the light switch that I outlined above)...that pig tail like symbol is a symbol for an 'inductor'...as current passes through it, it generates an electromagentic field and pulls the switch to it's left (still inside the Tail Light Relay) closed.
When that second switch closes, it allows current to flow now through the 15A Tail Light fuse, then on to all the light bulbs in the dash, and onto all the Tail/License plate lights/side markers and finally into the Headlight Cleaner Relay.
If you measure 12V+ on the far side (away from the battery) of that middle fusible link, then that fusible link is still good.
If you measure 0V with the light switch off and 12V with the light switch on (both one and two clicks) at the battery side of the Tail Light fuse, then the Tail Light Relay is good (or follow the procedure in the FSM to pull and test the relay).
If the Tail Light Relay checks out good, then if you measure 12V with the light switch on (both one and two clicks) at the far side (away from the batter) of the Tail Light fuse, then the Tail Light fuse is good (or pull and visually inspect and measure resistance across the removed fuse).
If both the Tail Light Relay and Fuse check out good, then if you measure 12V with the light switch on (both one and two clicks) at the tail light(s) socket(s) then the wire from the fuse box to the tail light is conducting properly.
With the light switch off, if you measure on the order of tens of Ohms (but not infitinity) resistance/continuity between the ground at the Tail Light(s) socket(s) and ground, then the ground wire is good.
If you pull and test the Tail Light bulbs for resistance/continuity and they read on the order of tens of Ohms (but not infinity) then they are conducting properly (there is continuity...ie. a path for conductance).
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Smoking Gun!
"so no reason to suspect it."
Major reason to suspect it. The previous owner put that CB there because that fuse kept blowing.
It does not belong in the fuse box.
Get a box of 15 amp fuses and start tracing the problem back.
- Thread starter
- #31
Thanks to all for your help. I have been slammed with family for the holidays and have not had a chance to continue the chase. Tonight after work.
@Trollhole, I'll get that manual scanned in today and get it to you ASAP. Sorry for the delay. Holidays.
@Trollhole, I'll get that manual scanned in today and get it to you ASAP. Sorry for the delay. Holidays.
Hold the phone guys. You are all correct in looking at the diagrams, but there is something much easier to check.
@R87FJ60 , got a couple of pointed questions for you:
1. Are your rear quarter panels rusted?
2. Do you live in a snowy area?
I had the exact same symptom and my problem that extreme corrosion of the terminals in the main body harness connector in the (US) driver side rear quarter panel caused the circuit to break. What had happened is that water got in there enough times to corrode the pins, and the one that broke first was the pin that provides power to the tail and rear running lights for both sides. I identified the pins that provided power for the running lights with a multimeter (test light works too), literally just pulled them out of the connector and spliced them together with a crimp connector for a quick fix. The permanent fix would be to pull the connector apart, remove the bad pins and replace with new pins, then assemble with dielectric grease.
That's a quick thing to check that's a known issue with the 60 series platform.
@R87FJ60 , got a couple of pointed questions for you:
1. Are your rear quarter panels rusted?
2. Do you live in a snowy area?
I had the exact same symptom and my problem that extreme corrosion of the terminals in the main body harness connector in the (US) driver side rear quarter panel caused the circuit to break. What had happened is that water got in there enough times to corrode the pins, and the one that broke first was the pin that provides power to the tail and rear running lights for both sides. I identified the pins that provided power for the running lights with a multimeter (test light works too), literally just pulled them out of the connector and spliced them together with a crimp connector for a quick fix. The permanent fix would be to pull the connector apart, remove the bad pins and replace with new pins, then assemble with dielectric grease.
That's a quick thing to check that's a known issue with the 60 series platform.
- Thread starter
- #33
@GLTHFJ60
!. no rust in rear quarter panels
2. fat meat greasy?
Yep, checked that. had the same issue with tail/running light wire connection at pins. excluded the pins...no luck. I think I may be on to something. I've been working on eliminating the trailer hook up. it was a hodgepodge mess. I've kind of got it torn apart but I'm not totally finished excluding it. I turned the lights on and now the front running lights are not on. This makes me think I've found something associated with the ground to the trailer lights. I'm off to work but should finish that up tonight.
!. no rust in rear quarter panels
2. fat meat greasy?
Yep, checked that. had the same issue with tail/running light wire connection at pins. excluded the pins...no luck. I think I may be on to something. I've been working on eliminating the trailer hook up. it was a hodgepodge mess. I've kind of got it torn apart but I'm not totally finished excluding it. I turned the lights on and now the front running lights are not on. This makes me think I've found something associated with the ground to the trailer lights. I'm off to work but should finish that up tonight.
@R87FJ60 Any luck on fixing this tail light issue?
I'm trying to help @gregnash sort through an electrical problem on his 10/85 FJ60 and I'm referring to the images of the wiring diagram from the Supplement you posted up in this thread, but wondering if you might be able to repost with a slightly higher resolution/light/focus...some of the two letter notations for the wire color coding are not possible to read...
I tried down loading them and opening them in another program and increasing the zoom, but the resolution isn't there....
Thx.
I'm trying to help @gregnash sort through an electrical problem on his 10/85 FJ60 and I'm referring to the images of the wiring diagram from the Supplement you posted up in this thread, but wondering if you might be able to repost with a slightly higher resolution/light/focus...some of the two letter notations for the wire color coding are not possible to read...
I tried down loading them and opening them in another program and increasing the zoom, but the resolution isn't there....
Thx.
- Thread starter
- #35
No...... Found the ground on the body behind the bumper. it was fine but i cleaned it up while I was there. Found the relay and it has continuity. cleaned up the trailer lights. been busy with work and holidays so just driving during daylight hours. which is a fairly narrow window in my neck the woods.
I had that entire supplement professionally scanned to a PDF and emailed it to Trollhole but have received zero response.?
I had that entire supplement professionally scanned to a PDF and emailed it to Trollhole but have received zero response.?
Alright. Thanks, I'll check in and see if @Trollhole has had a chance to upload it to that website...
I don't know what is going on with these Tail Light circuits but there are a bunch of threads out right now with folks having electrical issues...but they are all different problems!!!
I'll take another look at the circuit once I get a better copy of the wiring diagram...
- Thread starter
- #37
I hoping to get back in the garage this weekend. let me know if he did not get that and I'll resend it or whatever needs doing.
Where is this main body harness connector? My 60 has been blowing Tail light and running light fuses non stop. My guess is a short. Either at the relay or in the harness...but I'm a little uncertain just where to start.
Driver's side rear quarter panel. Pop off the interior panel and look down, you'll see it.
Thanks I'll take a look today. It's interesting...if I use a test light hooked up to battery (+) and probe each light socket of the tail lights. I get a ground on every single one...uncertain if that is normal.
