Very weird electrical problem - help!

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Erik

Full Access Member
Joined
May 31, 2017
Posts
70
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31
Location
Charlotte, NC
First Name
Erik
Truck Year
1974
Truck Model
C20
Engine Size
350
I am having a very strange issue with my '74 C20. I was changing the headlight switch today and when I was trying to pry the wiring harness off the old switch, my screwdriver accidentally jumped the white and red wires, creating a spark. (Something I found online says white is ground and red, as usual, is 12v unfused from the battery.) After I got everything all hooked back up and the dash put back together, almost nothing electrical works any more. The truck won't turn over, no headlights, no radio, no blinkers. The interior dome light works when the door is open, but not when I twist the headlight knob. One brake light works (it's possible the other is burned out and I didn't notice until now). When I try to honk the horn, it makes this sad little electrical noise, but no honk.

I looked at the fuses and they look fine (I haven't tested them with a multimeter). Could I have blown a fusible link? I located three - two near the starter and one on a wire bolted to the firewall kinda near the AC accumulator.

Any ideas here? To test a fusible link, do I just stick the multimeter probes into the wire on either side of the fusible link and look for very low resistance?

Any help would be greatly appreciated.
 

Honky Kong jr

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Denver,PA
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J-me
Truck Year
87
Truck Model
V10
Engine Size
Lil BB 407
I am having a very strange issue with my '74 C20. I was changing the headlight switch today and when I was trying to pry the wiring harness off the old switch, my screwdriver accidentally jumped the white and red wires, creating a spark. (Something I found online says white is ground and red, as usual, is 12v unfused from the battery.) After I got everything all hooked back up and the dash put back together, almost nothing electrical works any more. The truck won't turn over, no headlights, no radio, no blinkers. The interior dome light works when the door is open, but not when I twist the headlight knob. One brake light works (it's possible the other is burned out and I didn't notice until now). When I try to honk the horn, it makes this sad little electrical noise, but no honk.

I looked at the fuses and they look fine (I haven't tested them with a multimeter). Could I have blown a fusible link? I located three - two near the starter and one on a wire bolted to the firewall kinda near the AC accumulator.

Any ideas here? To test a fusible link, do I just stick the multimeter probes into the wire on either side of the fusible link and look for very low resistance?

Any help would be greatly appreciated.
Cut it out and replace it with an inline fuse holder.
 

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