Generator Output Test

NOTE: Battery and cable clamps must be clean and tight to ensure accurate meter indications. Before performing any generator tests, inspect the drive belt for looseness, damage and wear. If necessary, adjust the drive belt for proper tension.






1. Connect the leads of Rotunda ARBST 010-00725 or equivalent, to the vehicle, observing proper polarity.
2. Connect current probe to generator output wire to measure generator output.
3. Turn OFF all electrical accessories.
4. Turn the ignition switch to ON position and read the rate of discharge on the ammeter.
5. START the engine and run engine at 1500 to 2000 rpm.
6. Slowly increase the load control knob on the VAT-40 until the highest amp reading is obtained.

CAUTION: Do not drop the voltage below 12 volts.

7. Turn OFF the load control knob.
8. Add the ammeter reading obtained in Step 3 and Step 5 for total generator output. If the amperage output is within 10 percent of its rated output, the generator is functioning properly. If the amperage output is below this specification, refer to the Symptom Chart. Symptom Related Diagnostic Procedures