easy question....how do i test for a bad alternator?? i have a multimeter. what do i put where, and what should readings are good, ok, bad???? run car when testing?? thanks guys

 

Put the meter on the battery terminals. You should see about 12.6V with the engine off, 14.0V with the engine idling, and 14.4V with the engine at 2000RPM. To do a simple load test: Run the engine at 2000RPM and have someone in the car run as many power accessories as possible. If the voltage level drops more than 1-1.5V, the alternator is bad.

 

someone told me this one time when the car is running take a wrench and put the head next to the alternator and if it is attracted to the alternator like a magnet then it is good.
now this is just "backyard" mechanic stuff and don't quote me on it, I would get the sucker tested at autozone for free.
BTW the above thing DOES work with a good alternator, I never tested it on a bad one.
later
biker

 

I wouldn't go sticking anything on the alternator. Just remove it and have it tested for free at a local auto parts chain store. If your alternator is bad you may want to have your battery tested as well. A bad alternator can kill a battery, and vice versa. It's best to have both in good condition if you want the longest life possible.

 

yeah the wrench is a quick and easy check, i use a screw driver, got to be careful what you touch and it isn't very accurate.

 

That wrench trick - which I would NEVER recommend BTW - only tells you if the alternator is charging. You still need to load test it.