Kohler 14RCA / 20RCA — Separate Excitation Procedure
Testing & diagnosis · Main field (rotor)
For the Kohler 14RCA / 20RCA, from the Kohler service manual.
Applies to: Kohler 14RCA, Kohler 20RCA, Kohler CH740 (14 kW models); CH1000 (20 kW models) engine, Kohler CH 740 engine, Kohler CH1000 engine
Before you start
- Hazardous voltage. Operate the generator set only when all guards and electrical enclosures are in place.
Procedure
- Disconnect the black FN and FP leads from the alternator at the brush holder terminals.
- Connect a DC ammeter, 10-amp fuse, and a 12-volt automotive battery to the FP and FN brush leads.
- Note and record the ammeter reading.
- Start the engine and check that the ammeter reading remains stable.
- An increasing reading indicates a shorted rotor; a decreasing reading suggests a running open.
- Check for AC output across the stator leads and compare to Section 1 specifications.
- If rotor and stator are good, check the wiring, fuses, and controller settings and connections.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Approximate ammeter reading = battery voltage divided by specified rotor resistance
Full service-parts list: Kohler 14RCA →, Kohler 20RCA →
Source: Kohler service manual. Steps and values are as documented; always cross-check against the official manual and any later revisions for your exact serial number before servicing.