Marker Light issue

[my86m1009]

Last night I had my truck hooked up to my trailer since i had to rewire some lights, after an hour or so with the light switch on my truck in the running position, the lights suddenly shut off, I started the truck and battery voltage is fine, i then pulled the switch and the headlights came on. I have headlights, stop lights, turn signals. I checked all fuses and they are fine. Anyone ever ahd this happen to them or know where to start looking for the problem?

 

[robertss]

it wasn't in a CUCV, but in a Scout I have. Same GM style light switch. It acted like it had a circuit breaker that tripped. you could turn it off and back on and it was fine. I had to replace the switch and it stopped.

 

[steelandcanvas]

It does have an-auto resettable circuit breaker inside. When it cooled off, the breaker reset and allowed the lights to work.

 

[Gamagoat1]

That was in the TM, wasn't it?

 

[my86m1009]

Where is the breaker located?

 

[steelandcanvas]

Where is the breaker located?

From post #3: It does have an-auto resettable circuit breaker inside. This would be inside the 3 lever switch. If you look in the Classifieds. there is a Member that will replace the breaker and clean the switch for postage. Look in Pay It Forward.

 

[salt6]

Last night I had my truck hooked up to my trailer since i had to rewire some lights, after an hour or so with the light switch on my truck in the running position, the lights suddenly shut off, I started the truck and battery voltage is fine, i then pulled the switch and the headlights came on. I have headlights, stop lights, turn signals. I checked all fuses and they are fine. Anyone ever ahd this happen to them or know where to start looking for the problem?

I'm in the same situation now. What three lever switch are you guys talking about in a CUCV?

 

[markx250]

Nice thread timing ... just did it to me. I finally got around to wiring up a license plate lamp that taps into the trailer wiring plug (no wire splice, just using a connector slide onto one of the plug prongs). Did a quick prelim test and it was fine. Then bolted it all down and plugged in and nothin.

No marker lights front or rear. All other lights are OK. Fuse is OK and marker lamp fuse has power to the circuit. Toggled the blackout light switch a few time to no avail.

I will let it set overnight and test it again in the morning.

By the 3-lever switch, I believe they are referring to the in-dash light switch assembly.

 

[markx250]

Looks like it is the light switch for me. I just pulled it and tested continuity between #1 (battery feed) and #6 (headlight) and this is OK but nothing between #1 and 3-4-5 (tailights).

Just to be thorough, I am going to run a 12v jumper to 3-4-5 to see if the lights power up.

Update #1, jumping from #1 over to 3-4-5 on the plug produces running lights for me again, so the switch was it.

Update #2, after looking at the wiring schematic more closely and understanding that there is a fuse for the headlight and another one for the markers, I noticed the note that #5 is the fused input for the markers. With the switch pulled, there should be, and is continuity from #5 over to #3, #4 and #2 (panel lights). Problem now is isolated from fuse box to the switch plug ... I have no continuity between the fuse block and #5.
Swapping the switch would have been too easy of a plug-and-play

 

[markx250]

Still no luck. I have no power getting to the #5 terminal for the light switch plug. If I feed power to directly #3 or #4 in the plug, I get marker lights. I am studying Warthog's wiring diagrams to try and trace the path. One point of confusion for me right now is that I would imaging that the #5 feed, like the #1 feed for the headlights, would have to go through the blackout switch, but I am not seeing that for the marker lights. Starting to feel like I am missing something obvious here.

 

[markx250]

Fixed it ... blown 5-amp courtesy light fuse ... the hard way. I was looking for power to the #5 terminal of the light switch (see attached pic). So I traced it back to the 12v constant slot to the left of the 20-amp parking/marker fuse, as shown in Warthog's diagrams. What I did not know from the diagrams until I disconnected the fuse box is this post is shared by a wire jumper going over to the courtesy light fuse. Checked that fuse and it was indeed blown.

Oh well, learned a few things, cleaned up the fuse box plug, got rid of some more sand/dust and cleaned up a few grounds for good measure.

Always check the fuses! My cheapo test light was broken ... otherwise that is the easiest way to go through them all.

 

[OL AG '89]

I am now experiencing the same issues. I just added a hitch and a "T" connector for the trailer wiring. I hooked up trailer and headed out. I stopped to get fuel and when I walked around to the rear of vehicle I realized I had no running lights. My turn signals work, my headlights work, but no running lights. I spent today checking fuses and bulbs, thinking the trailer wiring had somehow put 24volts to the running lights circuit, but bulbs were good and all fuses checked to 0 ohms ( not open). I closed for the evening and set the alarm...... Well all of the running lights flashed, as they are wired to do.... So now I'm really confused.
i haven't checked the grounds as suggested, but I will tomorrow after work.
i have never had any wiring issues with this truck until this.

 

[OL AG '89]

I am wits end. I have pulled and replaced EVERY fuse. I just replaced the headlight switch and still nothing.....
what else can I check?

 

[nyoffroad]

I had a simuler problem and turned out to be a poor connection at the fuse itself. I ended up cleaning the terminals (after unhooking the bats!) and gave the fuse box terminals a slight sqeeze to tighten them up, I also gave the fuze blades a slight twist. That was a couple years ago and no problem since.

 

[nyoffroad]

I am wits end. I have pulled and replaced EVERY fuse. I just replaced the headlight switch and still nothing.....
what else can I check?

Have you checked for power at the fuse box? If not do so with a SHARP pointed test light, if it lights see my other post above. If not take a look under the hood on the driverside of the firewall, see that heavy red wire comeing from the passenger side and going to a little black terminal? Pull that apart and clean well. Good luck!

 

[OL AG '89]

FIXED!!!
i took the drivers seat out and assumed the dying roach position..... Something I learned from working on GAMAGOATS....
Anyway, I again took all of the fuses out and replaced with a NEW fuse, quicker than ohming out every fuse while squeezed under the dash. I also checked the ground wire from the dash. I pulled the connected, took an Emory file to both points and reattached firmly. At this point while pulling on the ground connection, I felt the E brake fixture move slightly. I noticed a bolt on the fixture and reached up to check its tightness. I moved it with my fingers...... So it appears that although there maybe other attachments points, this may have been the issue. I again checked the master power switch connections, removing each of them, cleaning and replacing. After all of this, I climbed back out, flipped the master switch and pulled the light switch and SUCCESS!!
i then took all of the fuses to the benched and checked each of them with my meter. All were good, ohmed to zero except one. The 5 amp dash lights fuse was open. I looked at it closely, but didn't see the break.
I got the trusty magnify glass out and sure enough, just a hairline break in the element.
This was 2 hours well spent and a hard lesson learned.
i hate electrical issues, but this one even more so because I "checked" the fuses......
HAPPY HUNTING!!!