Whats this wire?
 

89 R3500. Its been hot and has power to it... it goes in the headlight switch and connects to another orange wire. I cut it to test...

Background, I am trying to find out why I have insturment panel lights whenever the key is either on or on the acc position.

Anyone? Thanks!

Re: Whats this wire?
 

Illumination wire I believe

Re: Whats this wire?
 

Or one of the parking light feeds from the fuse box. This burned up on our ranch truck - orange wire from the fuse box up to the switch.
I ended up unwrapping a lot of the harness and pulling out all the burned/melted wires. In our case it was a gooseneck trailer short that took out the parking light wiring plus this feed. Poor quality fuse that didn't blow didn't help either - started a fusebox fire.

Quite a mess to clean up.

Re: Whats this wire?
 

Finally had a chance to work on this... with the wire cut I do not have any park lights.

I untaped the harness back to the fuse box and the wire got better looking the farther away I got from the headlight switch. I think its time for the solder gun to replace the wire.

This is on my wrecker, so I have a few more lights than stock... Maybe its time for a relay setup...

Re: Whats this wire?
 

Definitely recommended. About to do the same thing on our truck as I want to protect the truck wiring from trailer issues. Already in stock form there's the extra lights for cab roof and tailgate. That's one thin wire they used.

Quite a few trucks I scoured in the junkyard too had semi melted orange wires from the switch. Quite a few had a larger than original fuse installed too. . . .

Re: Whats this wire?
 

Any idea where the other orange wire goes that is connected to this one?

The orange wire comes from the fuse box to the light switch, then is connected to another orange wire that disappears back into the harness.

Re: Whats this wire?
 

Don't remember but I have the factory manual and once I find it I'll look it up for you.

Re: Whats this wire? Update...
 

Update... I ended up adding a relay and an extra fuse to the system. The orange wire is now just a signal wire to activate the relay, so no more 'load' and hopefully no more burnt wires. I placed the relay on the firewall next to the wiper motor and used the junction block for power, with an inline fuse. I used a factory relay and a factory fuse holder sourced from a parts truck so the setup looks factory.