Quote
Autozone hooked up a box to the system and said all was fine.


Their box said the same thing about my battery (which was 5yrs old and bulging on the side) and my alternator (that was causing my headlights to pulsate). Doesn't seem to be a very in-depth test unfortunately.

Personally I just replace both if I'm at all in doubt, which I figure costs about the same as having a knowledgeable shop do a thorough diagnosis.

98 Montero, 184k.