how to tell if your alternator is not working?

#1
i havent researched yet but how do you tell you if your alternator isnt working?
i suspect its not since my battery is dead .. it jump starts and runs fine.. but when you turn it off it wont do anything but click. Its a yellow top-ish battery i got less then a year ago..

Thanks
Mark
 
#2
no accurate way without a meter. try unhooking your neg cable after it is running and see if it shuts down. dont rule out the optima i have had plenty of them take a poo
 
#3
You can check it at the battery with a multi meter, but that only tells you the voltage. The amperage is the other part you need to know.
By what you describe, it's sounding like the battery.
 
#5
you should be able to start your jeep and unhook the battery and it run from the alternator.

With a yellow top optima it should stay charged for a year I would guess.

I my brother has left his cherokee parked for months and it cranks right up and its a cheapo battery.
 
#7
im going to attempt to bring it back from the dead by swapping it out with the other xj's battery.

if the yellow top "revives" then its possible the alternator is faulty or i have a bad drain somewhere..

Mark
 
Top