Little Help? Open Door or Turn on Light and Radio Goes Out

[jb3t]

So this is a wierd one with my 78 C10. I have an after market retro radio that's been working great. Tonight, I simply added an extension to the audio cord (for an iPod plugin that I snaked under carpet). When making sure the wires under the dash were not showing, the dome light went out, as did the stereo. Then, I closed the door and tried the stereo again and it came on. Then I opened the door and the under-dash light came on, the dome light did not, and the stereo went out. Then Inshut the door again and was able to turn the radio on but when I turned on the light (using the headlight control), the under dash light came on and the stereo went out (no dome light). So... When the lights are on, the stereo goes off.

I did not touch any wires when doing this, I simply tucked them up under the dash. I checked every wire and do not see anything shorting. The stereo is grounded. The stereo appears to be wired into the same wires that run the internal lights.

Any clues? This is a head scratcher. I've checked everything I touched.

[homemade87]

You have lost a ground wire . Everything is searching for a ground .Things like this happen when you loose a ground wire . Most likely with the lights sense the radio is wired there . Move the power supply on the radio the fuse box . That's where it should be anyway . Once you get that done start looking at the lights .

[jb3t]

Thanks.. I figured as much. I was gently stuffing wires under the dash and I must have lost a ground. I will get my head under there in the daylight and see what the issue is. I will also wire the radio right to the box as it should. Somewhere along the line, the previous owner did some hack job electrical work.

[Super_Dave]

I had a similar situation this weekend on my project, only in reverse.

When I got the '74 it had an aftermarket stereo installed but it didn't work. We removed it from the dash and followed the wires only to discover that the PO had disconnected the stereo from power. We reconnected it and got sound, however, when we closed the door, the stereo would die... open the door and it came back on. We eventually discovered that three of the four speaker screws in the drivers door, when installed, would shut down the stereo. It was grounded, so we couldn't figure why three of the four speaker screws were causing issues... even after putting electrical tape on the front and back of the holes, it still had an issue when the speaker housing made contact with the door.

I always save bits and pieces from projects, so went to my junk drawer and got four of those split plastic molly screw inserts... just happened to have four that were small enough, pushed them through the holes and screwed in the speaker. The plastic lip on the inserts kept the speaker housing from contacting the door and everything worked fine... It's still a crappy stereo, but it's better than being alone with my thoughts...

I absolutely hate anything electrical. It's about the only thing I can't wrap my head around.

[jb3t]

Wow... Hopefully I don't have to go this far. Everything WAS working perfectly until I tucked some wires (very carefully mind you) behind the dash a little further. Praying for a simple ground.