the car would run fine for a few days or months then one morning out of the blue the car would be stone dead. you could charge the battery and it run fine until it mysteriously goes dead again. numerous new batteries have been put into the car and still the car would be dead out of the blue. no lights or anything are being left on. so could it be the battery or altinator or a bit of both??? im new here and im trying to solve this problem for my girlfriends uncle. any help or response would be great

 

I had a 2010 silverado did the same thing. Under warrenty I took it to the dealer, they claimed the radio was drawing too much when the truck was off, wasn't that, they replaced the battery, wasn't that. Never found out what it was as it was a company truck, and went back when I retired. It certainly could be in your case radio drawing too much current that is draining the battery. Odd thing is I'd think it would do it overnight everynight. Your going to need a clamp on amp mete. Check each device that has power with key off, pull individual fuses till you find what is draining the battery. Only thing I can think of that draws power with key off is radio. I should add, check dome light, my son had a dodge dakota did the same thing, his dome light had a short in it.

 

thanks for the reply. i was tinking it cud be the altinator not char ging the battery wile driving?

 

It could be. I have only seen an alternator work, or not work. I assume this has the light, and not a voltmeter. Does the charge light work, and does it come on at all? You can certainly check the output of the alternator with a voltmeter, but if it is sporadic, you will have to monitor it. If it is sporadic, again I've never seen one. I'd suggest get an inexspensive voltmeter, wire it to the battery with enough wire you can monitor it while driving.