NOTE: Any multimeter reading of zero voltage indicates an open circuit.
Check for open circuits.
Turn the keys witch to the ON position.
Connect a multi meter, Part Number 3164488 or 3164489, to the following locations:
• Alternator “BAT” terminal to ground
• Alternator blade terminal “number 1” to ground
• Alternator blade terminal “number 2” to ground.
Locate and repair the open circuit.
Connect a carbon-pile load (battery/alternator tester) across the batteries in one of the battery boxes.
Clamp an induction pickup-type ampere-hour meter around the battery cable; or use the digital multi meter,
Part Number 3164488 or 3164489, with the clamp-on current probe, Part Number 3164490.
Disconnect any cables that lead to any other battery boxes in the circuit, negative (-) cables first.
Operate the engine at high idle; and measure the alternator voltage output to the batteries with digital
multimeter, Part Number 3164488 or 3164489. Refer to the OEM specifications.
Operate the engine at high idle and adjust the carbon-pile load-testing equipment to apply the maximum rated
amperage load to the alternator. Refer to the OEM specifications.
NOTE: The alternator maximum rated amperage output is normally stamped or labeled on the alternator.
Measure the alternator amperage output. Refer to the OEM specifications.
If the alternator output (amps) is not within 1 0 percent of rated output, repair or replace the alternator. Refer to the
OEM service manual for repair procedures.
Shut off the engine, and remove the test equipment.
Connect all battery cables, negative (-) cable last.