Short circuit

[Dennis Wilkie]

I've got a 1992 K1500 with an electrical problem. My courtesy lights and aftermarket tach are flickering, so i've been going through the wiring. I noticed that my ground on the courtesy light was showing .3v with nothing on and the doors closed, but when I opened the door, it showed 12v. I've spent at least 10 hours trying to track this down with no luck. I've got an aftermarket sound system, and instead of dealing with this headache anymore, I was just going to pull the fuse and leave it alone. So I pulled the courtesy light fuse, and the lights went off, but the radio also wasn't getting power. I don't know what the previous owner did with this wiring, but i'm about sick of all of it at thia point. Shouldn't the radio still be working without the courtesy fuse in? It sounds like the 2 power sources are somehow connected, but that still doesn't explain the 12v on the ground side

 

[packer0440]

I've got a 1992 K1500 with an electrical problem. My courtesy lights and aftermarket tach are flickering, so i've been going through the wiring. I noticed that my ground on the courtesy light was showing .3v with nothing on and the doors closed, but when I opened the door, it showed 12v. I've spent at least 10 hours trying to track this down with no luck. I've got an aftermarket sound system, and instead of dealing with this headache anymore, I was just going to pull the fuse and leave it alone. So I pulled the courtesy light fuse, and the lights went off, but the radio also wasn't getting power. I don't know what the previous owner did with this wiring, but i'm about sick of all of it at thia point. Shouldn't the radio still be working without the courtesy fuse in? It sounds like the 2 power sources are somehow connected, but that still doesn't explain the 12v on the ground side

According to the wiring manual the CTSY fuse powers the radio memory and clock; AKA the constant power. It's possible your sound system needs this to function.

 

[Dennis Wilkie]

My tach and courtesy lights flicker all of the time. I just went through everything again a little while ago, and I can't find anything out of place. I soldered and used heat shrink on all of my connections. There's a brown and a grey wire that comes directly off of the convenience center that both show 0 voltage, and the brown is supposed to go to the ashtray light, and it somehow supplies the power to that circuit with the cigarette lighter and glove box light. The 2 courtesy light circuit wires are orange (constant 12v +) and white. There's not much to the circuits, and that's what's confusing about it. But here's the weird part...I accidentally touched the orange (+) courtesy circuit to metal, and it blew the heater/ac fuse.