Rear Tail Light Signal

[Aussie81]

Hi All

I'm having an issue where my tail lights aren't working at all in my 81 El Camino.

I have LED digitails installed but don't believe they are the issue as theyve been working for years. I got my car back from the mechanic a few months ago and noticed my fuel gauge wasn't working and then recently noticed my tail lights weren't working either. My front lights/indicators work fine.

Things I've checked:
- tail lights fuse has power both sides
- test light on power wire into the digitails confirmed
- ground wire looks good
- checked signal out of the steering column wires with indicator on, can see power pulsing with the indicator signal
- when I test corresponding signal at the digitail there no power pulsing.
- I understand the fuel gauge is linked in the same harness to the rear so is likely linked.

Based on this info it appears there is a break somewhere after the signal splits off from the front lights, I just don't know where this is, I've looked under the dash and it goes into the main harness which makes it impossible to follow. Can anyone guide me on what to look at or where I can locate potential faults in the signalling.

Thanks in advance

Christian

 

[ELCAM]

There is a connector next to the left side of the fuse box that goes to the rear of the car, the harness goes from there down the kick panel behind the emergency brake from there it goes into a flat plastic plastic sheath that runs the length of the rocker with the aluminum body by fisher plate over it.
from there it runs inside the side of the spare tire and whatever compartment at the back wall of that compartment through a rubber grommet to under the body where it runs in split loom conduit on top of the frame to the back of the car.

First place i would look is on top of the frame above the rear wheel area since the split loom disintegrates eventually and the wire is there to endure what ever the tire throws at it.

I believe some are made with aluminum wire and prone to break anywhere it is not supported well.

 

[Aussie81]

Thanks ELCAM for the quick response. Is this the part circled red you're referring to? I assume so as I used a test light on the front but no signal however on the back the light was pulsing on the yellow wire. I cant unclip it or push it in any further but I think I may have found the issue.

Anyone have any issues with this clip/plug or have removed it? I'm mindful of forcing anything with brittle plastics.

 

[Sweet_Johnny]

The fact that one of the fuse slots is completely melted is alarming. You might notice that at least one other appears to be slightly misshapen due to heat, possibly because of the shared pathways inside. Check out the Stop/Hazard and Radio, as I think they might share a lead... I don't remember 100%. If you haven't separated the two halves I think that would be a good place to start. I'd also consider it fairly important- electrical shorts can burn your car down quickly.

 

[Aussie81]

Yes thats the AC fuse, it melted due to resistance in the fuse with corrosion. I saw it smoking one day and thankfully pulled over and switched the car off in time. An auto electrician bypassed the fuseblock with an inline fuse.

I didn't realise you could split the block. Thank you. I need to work out how it splits. Any insights or help would be appreciated.

Thanks

 

[78Delta88]

Ground wire... "Looks good"... Which one? I believe there should be a 14 mm bolt head, speed bolt on inside left side frame near bumper bracket. Very typical rusts out and you have problem with lights and fuel pump/fuel sender.

 

[Sweet_Johnny]

I have not separated either of my G Body fuse blocks, but I believe they're called a C100. I did separate the one on my '77 pickup and had to completely remove it, putting inline fuses in place. I found that many power and ground lines were shared among different circuits, indicating that a bad enough short could affect a completely separate system. In other words, that hot A/C fuse might have messed up the wiring for the lights if they share a power or ground.

If I remember correctly there's a bolt in the center holding it together, accessible from the engine bay side. Then both pieces pry apart, though there's often a tar like substance used to glue/seal them in place.