strange running tail light issue

[slackinoff]

Hey everyone. Love this site!

Ok when I bought the 81 last month, the fuse was missing on the running lights/dash ect spot. I stuck a 15A in and it popped when I turned the headlights on. So I went through the wiring and cleaned up a ton or jerry rigged tail light connections under the truck. Most of it seems to be OEM and still in the sheath that runs inside the driver frame rail. I followed it all the way to the engine compartment where it meets the other side of the fuse block.

I stuck stuck a 40a in just to see if I could get power at the brown wire on the headlight switch......well I do, and the running tail lights work now. Problem is, that brown wire gets pretty hot within about 10 seconds, I am quite sure it would melt if left on.

What part of that circuit do you think has an issue?? The instrument cluster is has always been dark/no lights. could it be something be inside of that gauge cluster?

Thanks guys, btw the stop lights, and blinkers do work.

 

[slackinoff]

ok so with the fuse in, the brown and orange wires get pretty durn hot within about 15 seconds. but the running tail lights work perfectly. the wires on the engine firewall side are cool as a cucumber.....what the heck is up with that?

 

[Georgeb]

ok so with the fuse in, the brown and orange wires get pretty durn hot within about 15 seconds. but the running tail lights work perfectly. the wires on the engine firewall side are cool as a cucumber.....what the heck is up with that?

Start tracing them and looking for anywhere they are pinched

 

[Georgeb]

The orange is the feed to the switch and the brown is the load from the switch. Not sure where the brown branches off but one brown goes to the rear and one goes to the front. Is there a trailer lights harness in the back? All that wiring good?

 

[slackinoff]

The orange is the feed to the switch and the brown is the load from the switch. Not sure where the brown branches off but one brown goes to the rear and one goes to the front. Is there a trailer lights harness in the back? All that wiring good?

HEy thank you for the reply!!!

I have only checked the brown wire going to the rear running tail lights inside the frame rail(green, yellow, lime green, brown).....and they work!!! they seem top notch and cool to the touch when on "running light position". In other words, From the engine firewall section, down to the back of the motor and inside the frame....all that wiring is super cool to the touch......it's just inside the cab, that brown wire coming from the light switch inside the cab;!! It gets hot when flipped on!

.......I guess I need to check the front brown wires? where do they go? the lower bumper lights?

I feel like I am so close, everything illuminates(even with it getting hot so fast right there at the switch).....but that dad gum brown wire from the switch is getting dang hot.....I don't dare leave it on.

Thank you guys@!!!!!

Any help would be awsome!

 

[Georgeb]

The brown feed to the front should run in the harness along the drivers side front fender. It feeds the parking lights in the front and the two marker lights in the fenders. It must be partially shorted to ground somewhere to cause the wires to get hot like that.