Howdy...I am new to the group and a "fair" mechanic meaning I do mostly simple stuff but I have a problem I'm not sure how to resolve.

I have a 1992 GMC 2500 Sierra 4X4 with a 454. The other day my wife was sitting in it listening to the radio with the engine off for about 20 minutes. Never had an electrical problem with it all but the next morning it would not start...I had to jump it off her minivan.... I could jump start it drive it an hour to work and at the end of my 10hr shift I would need another jump; and the same thing the next morning. After a few days of jump starting it I bought a good strong battery with 700 CCA. The next morning after installing it started and drove fine...at the end of my shift it was dead. My volt meter reads just shy of 14 volts but it has always read that.

I started disconnecting my battery when I park it, but today I found that if I disconnect the positive cable from the battery while the engine is running it will continue to run until I kill the ignition.

Any help or advice is appreciated...

 

Have ur altnator tested. it may not be charging as it should be.

if alt is good check see if ur radio cuts off with truck off, or inter lights.that's draining battery, but sounds more like alt , cuz take long time to drain a battery.

 

Ghost nailed it. It's most likely going to be an alternator issue. As far as it continuing to run with the battery disconnected, as long as that alternator is going, it will keep running. The batteries job is to start the vehicle. After that, the alternator will keep it going for a while till you toast it.

 

Thought I would share the resolution...my wife sat in the truck listening to the radio with the key in the "ON" position that created a constant current thru my fuel pump realy. As a result my FP relay burned closed and created a constant current to my fuel pump. I replaced my relay and had no more problems.

 

I'm glad you got it resolved! Thanks for reporting back - not many people do that.