MadStang
Well-Known Member
First step would be to set it to read DC volts. Start up the car and turn on the A/C and headlights (put them on highbeams.) Touch the Voltmeter leads to the Battery and see how much voltage you have at the battery while it is running with the accys on. You should have at least 13-13.5 volts. That will tell you what the ALT is putting out, and only takes 60 seconds to perform. You can also unhook the batt and check the voltage. leave it unhooked and check it later (at least a couple of hrs, the longer the better).
If the voltage has dropped sufficiently while unhooked, batt is not holding a charge. You can do this test hooked up to the car after you verify the batt is ok. You dont need an expensive volt tester, but I would suggest a digital from sears. Let us know what you find.
I might do it an easier way (for me at least) and datalog the results with my SCT. I can check the voltage through the handheld and it's a digital read out.