evilfocus

my computer is acting weird, every time i try to open the fsm link, my internet explorer closes on me. can someone post the instructions on testing your alternator? or if you know how, let me know. thanks-jake

Icemark

You get a multi-meter that can read in 100+ amps, and see what your alt is putting out under load

eriksseven

iTrader: (6)

Call your local autoparts store and see if they have a tester.

Icemark

most autoparts stores, can only check the rectifier circuit (diodes) and don't really have the ability to load test.

Load is where our alts fail... the little bit of AC that makes it through if there is a bad diode is meaningless.

eriksseven

iTrader: (6)

Good point.

When I've used "their tester" (that has a walkthrough) it tells you to turn on the headlights, run the heater or A/C and bring the rev's up to 3k RPM's. Not sure if that's a "full load scenario" though...

Project88Turbo

iTrader: (22)

The Bear ARBST vehicle tester we have at Advance Auto is pretty nice. It measures the amps, volts and RPMs. During the test you have the engine @ 2K and it puts an electrical load on the system. It's enough of a load that a car with a bad alternator and low battery will shut off completely. Also during the test it can determine if it has bad diodes. And it has multimeter leads so you can check for battery voltage at the Alternators B+ terminal so long as it is easily accessible. I think it's a pretty comprehensive test.

It can also test 6V and 12V batteries, and do check your starter basically be measuring the amps required to start the engine.

Vince