Sorry not sure if this is the right place to post in but I got back to town from work on friday and my truck wouldnt start. I boosted it off the work truck and she fired up. I drove home probly a 5-10 minute drive and was home for probly 1 hour max then left everything was fine. Got back home later parked it for the night and went out to start it the next day about noon at it was dead just a click thats about it. I got another boost let it run for quite awhile drove it for awhile and hasnt happened since yesterday. It started fine this morning and so far today. I dont wanna need another boost when I get back to town next friday. Would this be the alternator or just a weak battery? GM wants $663+ for an alternator NAPA cant get it. And if its the battery, will I have to replace both?







Sorry for the lengthy speal.

I'd check the alt. first. Just test the battery with the engine running, you should measure 13.8 - 14.2 volts if youre alt. is working.

The guage reads a tick or 2 above 14 while driving. So is it overcharging? Its not extreme just slightly past half (14V). Been fine so far today. If it was the alternator would it still keep running? Will an alternator show signs that its starting to go or will it just go? I'm starting to lean towards a weak battery. The truck has always been driven every single day up until bout may when I switched jobs. Now I'm outta town all week and we only get to hang out on weekends, haha. So maybe its just sitting so long now that its getting cooler (not as cold as it usually get though this year) and the battery's getting weak? It is still both stock batteries.

So is it overcharging?

No that's normal. I meant to use a multimeter accross the battery, but if your in dash voltmeter is reading above 14v while driving, it's prety safe to asume that the alt. is working. Besides, if it were not, you would'nt get very far.

I think your having the same problem I am, that your batteries are near the end of their life. You can have them load tested to verify. My batteries measure good when charged, but are almost 4 years old. So I think I'm going to just replace them soon.

That's what I figured but wanted to make sure. Mine are the stockers so bout 4-5 years old so I figured they must be getting weak. Havent had troubles since saturday morn (knock on wood) so that must be it. Do both batteries run off each other though , like will they charge each other or is one just for the accesories or somethin?

Yeah both batteries are connected to each other.

So if its a weak battery I'll be needing to buy 2? Just wanna make sure I'm understandin here.

Same thing happened to mine about 2 months ago. Bout $170 later after a discount I have 2 new batteries. You can try charging them but if they were as bad as mine they won't hold, plus it's a pita because they have to be done individually. Yes you need both

Been good so far but I guess I'll wait n see. If they Die again I guess I'll just replace em both. Any preferences on brands? I guess whatever works works but I never buy economy. Also I've never had to buy a battery before, How do I pick one out? or do I just tell em make/model at the counter? Sorry I seriously never had a battery problem before.

Figured I'd give an update while I got Net access in the hotel (sigh). Replaced Batteries $240 at NAPA with a discount, ouch. Anyway been good since. Beats the H#!! outta the $700 alternator GM priced for me I guess.