No Dash lights, tail lights or Marker lights But Headlights, brake lights work?

[jr1224]

Was thinking about other places to check after looking at the tail light diagram (see pic)
1. Fuseble link
2. Red wire that runs from relay to fuse block?

Little puzzled but what do you think?

Need to figure this out

 

[blkprj80]

Problem is between green circuit (above) and ground.

If you take out any of those lamps and ohm across where the lamp was, you will likely see zero or very few ohms. That is your short you are looking for. Now you have to figure out where it is.

Somewhere in the manual you will find where all those splices and connections are supposed to be located. You're looking for a green wire shorted to ground somewhere.

If you replace the 15A TAIL fuse with a simple lamp that draws 5 amps or so, at 12V, you can use a sensitive voltmeter to find your short. Then you won't smoke your relay. This will likely be a really bright and maybe hot headlight or similar.

If you put a lamp in as above, and measure all the green wire connections shown in the diagram, with respect to chassis ground, the lowest voltage reading is the one closest to the short in the harness. You should be measuring millivolts, not volts.

Good luck with it!

 

[jr1224]

Think I'm getting closer I unplugged the connectors in the rear quarter panel driver side (see pic) and the larger connector has two slightly burned looking connections (see pic of both sides). When I connected this plug the taillamp fuse immediately burned out. With it in plugged my gauge lights worked and front marker lights too. How the hell do I replace this plug?

I checked out the rest of the bundle that runs from DR side back to rear and it looked intact till I got to this plug.

Help, feel like I'm getting closer. If the front marker lights and the gauges work with this plug undone. But when I plug the rear section of the plug in the fuse blows does this mean that the short is in the rear section part of the plug? Now what?

 

[jr1224]

Starting to think that this is where the problem is the wire that plugs into the female & male side of the plug are green which is denoted in the tail light wire diagram above. Haven't checked on this yet but I'm guessing that there is no replacement for this plug (probably outside of a full harness which would be expensive and complicated to change up). Can I clip these two wires from both sides add the same gauge/color wire to jump the plug? This would allow me to keep searching for other things to check if it doesn't fix the problem. Get my taillights back up and rig on road. While I figure a more permanent And cleaner fix.
Thoughts??

 

[SUMMIT CRUISERS]

I would clean and brush the connector contacts and spray down with starting fluid. To be safe, I would disconnect the battery before doing so. Each wire is isolated from the other with plastic. It appears there is corrosion between two of the wires and a good cleaning will help. Not sure if your short is coming from the connector, I don't see any burned or melted spots, just corrosion. I would then ohm out the wires to ground on both sides of the connector and then figure if one of the circuits is shorted out via wiring diagram and proceed in that direction. Lastly, you could cut out the associated wires with the connector and bypass.

 

[fatfish]

If you have not ruled out the module for the trailer lights I would do that before I would start cutting up your wire harness. It's just a matter of disconnect 2 plugs near the jack and 2 more behind the pass side rear panel. This will take only about 5 min, and will eliminate a aftermarket part. These just plug in between 2 plugs on the factory harness. The one by the jack and one on the other side. It also has a wire that runs between the 2 connectors. On mine the wire is yellow, and runs under carpet across the back.

 

[jr1224]

I've got lights.. HOORAY.. I cleaned out real good the plug (pictured in previous post wire brush and contact cleaner) got in nice & dry. Un plugged the two next plugs which go to the

other side of car saw the had dirt & stuff on them (cleaned them up well too) went over to passenger side to look at trailer moduel (see pic)

Learned that the wires to the speaker on rear pass side were butcherd in by PO. Fixed a few of them that looked crappy ( I mean come on use a connector at min/ not just Etape). Sloppy crap pisses me off.
I put the plugs back together (trying to isolate the problem). Everything is back together all lights work (I've tested them a few times so far so good). Here is what I've learned.
1. Don't be afraid of electrical stuff( be prepared get a good multi tester, / learn to use it)
2. If you see something that is broken or sloppy along the way.. Stop fix it, keep looking.
3. I need to rewire the tow trailer stuff with a good kit. Do it nice and clean Mud research on this here I come.
4 noticed I need to clean the ground take down spare tire clean and redo.
5. Get all new speakers wire them in right. If this rear one is any indication the others are the same. Will need to see what sizes I need to get.

Main thing I've learned is my Mud brothers are awesome. I'd be lost without you guys. Tomorrow is my birthday and you guys and Mud are a terrific gift.

Thank you Thank you thank you.
Sorry for the long post and will keep you posted..

 

[blkprj80]

I don't think you've fixed it. You've only made it go away for a while.
You never found a smoking gun.

A bad or dirty connector cannot blow a fuse, unless maybe with saltwater or metallic debris.

Since the problem went away when you messed with the trailer light module, I'd start there. So many others have had a bad module, so that should be your first suspect.

Glad you have tail lights again, for now. Good luck finding the root cause.

Oh, and HAPPY BIRTHDAY (tomorrow)!

 

[jr1224]

Yep I'm looking up trailer wire kits. As I think the problem is most likely there. The last time I towed I had issues with getting a good ground for the lights to work on the trailer that was over a year ago I think the ground above the spare needs some TLC the trailer wiring needs to be redone. But yes no smoking gun nor a repeatable issue I could replicate. Job not done but will keep on it and will keep working the multimeter...

Thank you for your help.

 

[INNOV8S]

I had a similar situation on my '92 FJ, no display, tail and brake lights. I checked the trailer connection area. There were two green wires going into a flat connector, one had rusted/oxidized out. Fixed that. There was also a white ground white that had a heavily rusted contact point, I re grounded that to a new, clean location. After I connected the two green wires -- I got display and brakes lights(no tail) to fire when pushing on break pedal only. I went through the debug Jon Held described. Checked fuse continuity - OK (I had just replaced it because it was blown). Checked tail light relay, using the jumper, connecting 2 and 3. Whoa, everything worked!! I figured it was the relay and ordered an new one from NH. It would be a few days, so I put everything back together, so at least we could move it around the driveway, or go on short runs. When I put the old relay back in everything work!!. I have been launching the boat lately, so either having that gree wire not connected or white wire poorly ground cause fuse to "pop" when coming into contact with water. I would not have been able to fix the problem on my own. Thanks brudder mudders!

 

[ScribeForce3FE]

Hi, I'm new to the forum and yes I am reviving this thread as I am experiencing similar issues and cannot seem to find the source of my short. Mine is 1992 fj80 and everytime I turn the knob the 15A fuse blows instantly. All of my lights had been functioning properly prior to this episode. My front side markers, dash lights and brake lights do not work. Also, reverse lights gave out. I have essentially eliminated completely all the trailer hitch wiring mess (which was on the rear ds not ps as someone had stated above). The PO had a stereo system and back up camera installed and again eliminated/disconnected all of that. I also checked that connection posted above to see if appeared burned or dirty but that appeared fine. Also while I was at the back end I removed some wires the PO had I'm assuming installed during the stereo system installation and were just screwed in with the opposite end just taped up (wires were not original). Also, fixed some wires that looked beat up. Since this is happening while in park I figured I would check the side marker bulbs and sockets for corrosion or rust but that seemed fine. Something to note is I'm not entirely certain that my side markers where working prior to this episode. I need to further chase the wiring and see if I find anything abnormal. I also removed the ds kick panel and removed the tail light relay plus it also felt hot and upon inspection it looks fine underneath. When I look at that relay and the others there some have what appears to be small circular spots of rust which I'm assuming must be from water droplets. I'm wondering if I should removed this relay panel and inspect posterior for rust/corrosion that is causing the short? Since the fuse is blowing instantly would the contact points on the light knob be more likely the problem or that is less likely? I don't have an fsm. Please help!

 

[Handznswayz]

What year is your truck? Do your reverse lights work? Have you checked the driver's rear quarter (jack location) for water?

I have a 92 geo prizm 4 cylinder 1.8 4 door sedan my dash lights don't work rear running lights don't brake lights will when pushed the light in my back window stopped working as well my tag lights ain't working either what can be causing this

 

[60 toy ota]

I have a 92 geo prizm 4 cylinder 1.8 4 door sedan my dash lights don't work rear running lights don't brake lights will when pushed the light in my back window stopped working as well my tag lights ain't working either what can be causing this

Not a ton we can tell you as this is a land cruiser forum and yours isn't even a toyota. That said, the general rules will still apply. Use a multimeter and test for continuity from the load side of the fuse (fuse removed) to ground. If there is continuity, you have a short. Find an applicable wire diagram and move the probe from the fuse farther down the circuit, disconnecting as you go, till you find the short.

 

[BILT4ME]

I have a 92 geo prizm 4 cylinder 1.8 4 door sedan my dash lights don't work rear running lights don't brake lights will when pushed the light in my back window stopped working as well my tag lights ain't working either what can be causing this

Odds are you have a taillight bulb burned out. They make it so you lose dash lights so you'll go look. Go to an O'Reilly's and have someone help you check and change the bulb(s).

 

[cmcmill01]

Having the same issue on my FZJ80 94, seems there is a lot of heat being generated in the Taillight relay.
This is the 2nd relay that I have had in and it looks like the 15amp Taillight fuse had been replaced with a 30amp.

I have replaced the fuse and a new relay, and connected a smart device that measures current through blade fuses, and its reading 7.50amps as soon as I turn on the lights.

All the lights are working Dash and rear and the 15amp fuse still holds but the new relay is getting very warm.

Anyone have an idea on what current should be flowing and what rating the Taillight relay is?

 

[joshrabon]

Thanks to everyone who posted, this helped a ton. Quickly narrowed my problem down to the tail light relay. I’ve had this issue intermittently and I think the culprit is the crappy auto zone relay I bought in one of my past repair attempts. OEM it is. Quick fix for me was to swap the horn relay for the time being.

Using the jumper and multimeter allowed me to quickly diagnose and show I had the correct voltage coming into the circuit!

Awesome thread. Thanks Mud!