Short to ground in dash

[78Delta88]

GMs are notorious for back feeds, and in that you have other circuits opened, and as others have pointed out..., let the fun begin.

As a dealership tech, back when these cars were new, what you describe isn't any thing new. Most memorable was a Firebird returned for warranty work. Car was about 2 weeks old. Open the door the radio started, close the door dome light comes on, radio does not work.

Root cause??? A penny fell into the cigarette lighter hole in the console between the seats.

GM is notorious for wire problems. You have to get the harness back to prior-problem status before you can really continue, before pulling fuses or checking relays.

 

[SoFloG]

How are you even testing for voltage at ground? What are you using. Something doesn't make sense. Are your battery terminals backwards? If you use a multimeter or test light and put one contact on a ground and another on a + source you will have a voltage reading. If you have 12v+ to your vehicle frame then where are you getting 12v- from?

 

[78Delta88]

How are you even testing for voltage at ground? What are you using. Something doesn't make sense. Are your battery terminals backwards? If you use a multimeter or test light and put one contact on a ground and another on a + source you will have a voltage reading. If you have 12v+ to your vehicle frame then where are you getting 12v- from?

It's most likely a back feed. VOM will show volts, but usually not enough amps to be patent.

 

[SoFloG]

You would not be able to have 12v+ running to or from ground without fire, or fuses blowing unless you literally have your battery cables backwards, and in that case nothing would work.

 

[SoFloG]

It's most likely a back feed. VOM will show volts, but usually not enough amps to be patent.

Then there would be a short.

 

[78Delta88]

Yes in simple terms.

 

[WesFischer05]

Without the engine and starter in the car how are you getting power to the fuseable links?

How are you measuring the power at the grounds? Testlight /meter connected to ground and where else?

The new engine is in the car sitting on motor mounts and is grounded to my frame. The starter is attached to it like normal and my power wires are connected to it and a battery connects to my starter

 

[jcelk]

feedback is if you undo the ground wire it will show voltage because volts are passing through the lights or what ever touch the ground wire to a good body ground if it doesn;t get real hot real fast there is no short bolt the grounds wires back up and see what works also clean and cheak battery termanels make sure batt is good you need 12 volts

 

[Rocknrod]

Any updates on this?

 

[WesFischer05]

Any updates on this?

Yeah..... My dome light shorted and I moved the two wires away from each other and it all works now! So kinda annoying that it was so simple but I got to fix some pretty bad previous work by whoever owned it before me in the dash.