Electrical Short?

[DON TX]

I have a 03 sierra 1500 that was acting weird when it hit a bump. The door locks may cycle, abs/brake warning lit up, a/c comp would quit and/or the engine would shut down to reduced power mode or shut down altogether. It seemed to happen when the air temp was over 85*. I took it over a real bumpy road and it quit altogether. It will not start and will only crank for a few seconds twice now and the battery is below the level to crank. The bat checks good. I've removed all fuses, relays, starter, alt and with key removed it still shows a draw on the battery. Anyone know what this means? I'm thinking the brain may be bad. Help!! It's my work truck and my wife wants her truck back. It has @ 185k miles. It was running great til a couple of weeks ago. No oil loss, still had good power and it shows no codes. TIA

DON TX

[redvett]

Check the grounds and battery cables, they must be clean and tight.

[DON TX]

Check the grounds and battery cables, they must be clean and tight.

 

That was the first thing I did. Thanks.

DON TX

[Easytide]

Had similar problem with an 03 Silverado. The live batt wire to trailer harness (the heavy red one for trailer Batts,ect) had partially shorted. Created nuff current draw to kill Battery and wreak havoc w/charging sys, but never blew the breaker.

[DON TX]

Check the grounds and battery cables, they must be clean and tight.

I finally found the ground wire that was causing the problem. It was the ground wire coming out of the bundle that runs over the engine from the computer. It comes out of the bundle and runs to the back of the engine block. It can't be seen until you remove the plastic cover on top of the engine and run your hand down the bundle going to the back of the engine and feel it go behind the engine. It had vibrated for 185k miles til it broke into and was resting on the connector til it was bumped. It might be a small or large pothole and different things would go wrong at different bumps. Totally unbelievable and a stroke of luck to find it. GM should find the engineer that let that obvious problem get to the stage of production and put him in charge of cleaning toilets. A simple rerouting or sturdier connecting point would have saved me a couple of hundred dollars and countless hours of searching for a simple fix. It nearly cost them a sale of a $28k 2011 Silverado P/U. Had I known this 2 weeks ago I would own a Toyota instead.

DON TX