The F67 function on MS004/MS002 benches acts as a built-in voltage regulator, allowing 12V alternators to be tested without their regulator.
MSG Equipment explained the F67 function of its MS004/MS002 benches for testing alternators, voltage regulators and starters. Named after the brush connection terminal, F67 acts as a voltage regulator built into the bench, delivering an output voltage set by the operator.
When a faulty regulator is found, simply fitting a new one and continuing can be a mistake, because the failure may have been caused by:
- A short circuit, including an inter-turn short in the field winding,
- A faulty rectifier bridge (diode breakdown).
Such faults could destroy the new regulator. With F67, the rest of the alternator is tested first using the built-in regulator; if no issues appear, a new regulator can be safely installed and tested.