how do test a regulator
To test the alternator, you need to excite the circuit by revving the engine above 2000 rpm. Turn on the headlights, stereo and heater blower to place a load on the electrical systems. Next measure the voltage at the Bat post on the back of the alternator or at the starter solenoid Battery terminal. This should measure between 13.5 and 14.5 volts.
If the system reads only 12 V, basically battery voltage, then disconnect the plug at the voltage regulator. Using a jumper wire with male connectors on both ends, place one end in the voltage regulators F terminal connector and the other end on the voltage regulators A connector. This effectively bypasses the voltage regulator and provides full excitation to the alternator. The voltage reading at the bat post should now read 15V. If it still reads only 12 V, then the wires to/from the alternator and the regulator are suspect.
Coach Jack
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