Cummins/Onan Energy Command 20 — Test Procedure
Testing & diagnosis · EC-20 controller
For the Cummins/Onan Energy Command 20, from the Cummins/Onan service manual.
Applies to: Cummins/Onan HDKA, Cummins/Onan HDKB, Cummins/Onan HDKC
Procedure
- Reconnect the genset negative (-) battery cable.
- Insert the fuses for Wire #7 8-35VDC Power, Wire #8 House Battery Sense, and Wire #9 Engine Battery Sense.
- Select the genset type per the Setting Up section.
- Set the hour-meter if the EC-20 is installed on an existing genset.
- Start and stop the genset using the Stop/Start switch at the genset to confirm genset operation.
- Start the genset at the EC-20 and verify: indicator light flashes while cranking, genset starts and runs, light stays lit, hour meter and volt meter operate.
- Stop the genset at the controller and verify: genset stops, indicator light turns off, hour meter stops.
Full service-parts list: Cummins/Onan HDKA →, Cummins/Onan HDKB →, Cummins/Onan HDKC →
Source: Cummins/Onan 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.