Hi,
I have a 2001 Chevy express 2500. Recently this past week I've had to jump it to start it every time I use it, I imagine it is the alternator. Usually I check the alternators with a volt meter, but this one is jammed way back in there and I cannot get to it easily. I was wondering if I could test it with a new battery? My concern is if the alternator is charging just under where it need to be, would it then take awhile ( more than a day) to drain the new battery making me think it was just a bad battery?
Thanks,
Corey

 

Load test the battery first. Not likely to be the alternator. Your voltmeter would show less than 13 volts while the engine is running.
My bet is the battery.
Also had to do the starter on my van, and a bad starter is hard on everything.
As for testing, just jump start it, and then put the voltmeter on the battery terminals. you should get 14 or so volts right after starting it......if not, then if all your wiring connections are good, then maybe yes bad alt....but lots to check first.

 

Were it the battery, the charge would slowly drain down while driving until the engine would eventually quit. If running, turn on the headlights and honk the horn. If the alternator is not charging the horn will sound really sick if it honks at all. Just after shutting down from a run, disconnect the ground wire on the battery and check the voltage across the posts. If you have only ~10.5 volts or less you have a bad cell.