No need. Go pos to neg on the battery terminals as the car is running. Should be 14v or round about.
Sent from my DROID RAZR HD
I think we are saying the same thing.
1. Place the red end of the voltmeter to the red battery terminal and the black contact to the black terminal, if the battery reads above 12.2 volts it has enough charge to start the alternator that can be tested with the voltmeter; if not, either get the battery charged and re-test.
2. Start the vehicle, turn on the headlights and have someone rev the engine to 2000 RPM. This will draw power on your battery that should cause your regulator to jump the alternator into high gear.
3. Retest the battery with the voltmeter, voltage will be at least 13. If varying the RMPs causes the voltage to fluctuate between 13 and 14.5 volts, your alternator is working well, otherwise if the voltage remains the same or decreases, your alternator isn’t working properly.