Confused

[Conundrum]

I have an 03 silverado that is my wifes daily driver, the battery had went dead a couple of times in the last month and considering it was 5 years old I figured it was time to replace it. So I bought a new one and put it in, and we are still having a problem with the truck randomly dieing on us when driving it.

I had the alternator checked at the parts store and it checked out good.

Any ideas on what it could be?

[463]

clean the battery cables (make sure there tight) & check the ground wire to the frame/block/body. extra draw items such as comand/security sat radio will draw down a battery. a test to see if the alt is working is to pull off the + or hot cable off the battery when your running, if the engine stops the alt is not charging. the computer should have a code stored re: randomly dieing when driving it.

[bwood]

Originally Posted by 463

pull off the + or hot cable off the battery when your running,

I know this works on older non computer controlled vehicles, but it has been my experince that the engine will die anyway and this could cause damage to the ECM.

[pilotj]

I had the same problem on my daughters 2004 Cavalier. Replaced the battery and it still would go dead at times. I was also having issues with interior lights and windows. It ended up being a bad body control module. I replaced it and had the vin flashed to it and havnt had a problem since.

[463]

Originally Posted by bwood

I know this works on older non computer controlled vehicles, but it has been my experince that the engine will die anyway and this could cause damage to the ECM.

if it's got a chance of screwing the computer don't pull the + cable off when the engine is running.

[truckdude239]

never ever pull the battery cables off when running. it will cause a voltage spike that will fry the computer. i've had alts test good but be bad normally all mine seem the diodes go bad and pull back off the battery when the truck is off

[bwood]

Pull the alt off and have it tested out of the vehicle. Testing it in the vehicle can make a bad one or one going bad still show good. Also who ever tests it (Oreilly and Autozone do it for free) have them do it a couple of times and maybe take it to a rebuilder and have them test it. Make sure the battery is clean also. Grease and buildup on the batt can simulate a small load if the buildup goes from terminal to terminal. I have also seen cases where the cable end looks good but if you strip the wire back the cable is full of corrosion. Something else to check would be to have the new battery tested. Take it out and put a good, slow charge on it and take it to have it tested. You could also charge it and let it sit on the bench for a few days and see if it drops drastically just sitting (you would need a voltmeter to check the voltage).

[Conundrum]

Thanks for all of your feedback, due to our work schedule and how early it gets dark and the lack of a garage I will have to try and get this fixed this weekend.

[Conundrum]

I unfortunately did not get the chance to work on the truck this past weekend.
Although the truck hasn't died on either of us while driving it in the past week, we have noticed a high pitched whine coming from the engie compartment for a few seconds during acceleration.
I'm thinking it is the alternator..

Any other thoughts?