Electrical Woes

[3MAX]

I'll start with a brief history of my project - just bought a '90 model Blazer as a project truck. The body & running gear are solid, but the PO really did a job on the wiring. I've already worked out a lot of issues, and thought I had it pretty well taken care of until last night.

The parking / running lights and buzzer came on all by themselves, with no one touching the truck. The light switch had no effect. I even unplugged the wiring harness from the switch, and the lights stayed on. I disconnected and reconnected the battery and the problem went away for a few minutes, then started again. Now, the parking lights (front and rear) & buzzer stay on as long as the battery is connected. So far I haven't had any luck finding where the circut is getting voltage from. I've pulled every fuse hoping to find where the power was coming from, but no luck. I'm currently tracing the wires in the parking light circut throughout the truck, hoping to find where it's getting power.

Anyone have suggestions???

 

[udy2554]

Was there ever an alarm installed. When I bought mine, the doors would lock on occasion. Periodically all the outside lights would flash. Some times the vehicle would not try to start. I got under the dash and traced all the wiring from a black box, disconnected them, chucked the box and about 50' of wire...no more problem!

 

[3MAX]

I'm not sure about an alarm, but they had definitely fooled around with the lighting. All of the running bulbs have been replaced with blue ones, and I pulled out an old strobe controller that had since been disconnected and as you said several feet of wiring.

I'm zeroing in on the problem, I now know that it's in the rear tail light wiring somewhere between the firewall and back of the truck.

 

[udy2554]

Have fun with that. I am on a break to pick up my tools. I've been under my dash since noon, chasing down a short I never found, but now everything works. Go figure.

Good luck with your search!

 

[3MAX]

Found it! The insulation had been worn through on a couple of wires where the harness was rubbing on the rear of the frame as it turned toward the left rear tail light. Amazingly, they didn't ground out on the frame, just shorted together. Fixed it up tonight & pulled some slack in the wires so it doesn't happen again.

 

[udy2554]