Another Tail Light Issue (Resolved)

[Clutch9800]

Hi All,

I recently removed a broken stereo from my 1979 Sierra 1500. There was also an Alpine amplifier tucked up under the dash.

Since the replacement, I have no tail-lights, back up lights, brake lights.

Turn signals work, but are quite dim and flash on both sides. License Plate light works well. All other lights on the vehicle work fine. Fuses have been replaced.

I believe I may have cut/disconnected a ground wire.

Can anyone point me in a good direction to identifying the bad ground and getting it reconnected?

Thanks in advance!

Clutch

 

[Charlie]

 

[Frankenchevy]

does it change with your stereo on or off? check your battery to see if its just drained. your tail lights should be individually grounded behind the actual tail light housing themselves, I'm not sure where else they may be grounded under the dash. make sure any ground that you disconnected and reconnected during the stereo installation gets sanded/cleaned before you reconnect it. paint and rust aren't great conductors. I'd trace the harness that comes from the tail lights into the cab and make sure everything is intact. you might have a 'hot' wire grounding out somewhere. there are wiring diagrams in the reference thread on this forum. your truck is 40 years old and wire shielding tends to get brittle and break when your moving it around while working on something. if you have any crimp butt connectors under there, I'd solder and shrink wrap them instead. I'm not an expert on these trucks by any means, but I did sleep at a holiday inn last night.

 

[Clutch9800]

Well,

I got under the dash and chased wires for a while. Capped and heat shrunk any wires to nowhere. Found any loose grounds and re-fixed them. Just general clean-up of a rats nest of aftermarket wiring and the such.

I then followed the advice in some previous tail light threads and got out the test light and the multimeter and checked for power and voltage at the tail light plugs themselves. Sure enough I had about 12.5 volts at the terminals when I connected the light and multimeter to a good ground point on the frame. So I ran a new ground from the bed to the frame and met with some success. I now have tail lights, turn signals, and reverse lights. But no Brake Lights.

The hunt continues!

Clutch

 

[Clutch9800]

RESOLVED!

Taking Frakenchevy's advice and recognizing that the wires are indeed about 40 years old, I started at the plunger switch on the brake pedal. Sure enough, the orange (hot) wire was hanging by a thread. A quick strip and crimp of a new connector and everything worked perfectly.

Thanks for the advice ya'll.

Clutch

 

[smoothandlow84]

Glad to hear that you found the problem.

 

[Honky Kong jr]

Glad to hear that you found the problem.

Nice avatar I like it!!

 

[smoothandlow84]

Nice avatar I like it!!

Hahah...I was waiting for you to comment...lol