Cummins/Onan — Troubleshooting the EC-30
Testing & diagnosis · EC-30 controller
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan HDKA, Cummins/Onan HDKB, Cummins/Onan HDKC
Before you start
- Improper service or replacement of parts can result in severe personal injury, death, and/or equipment damage.
Procedure
- Determine if the genset operates correctly from the genset controls; if not, the problem is in the genset, not the EC-30.
- Confirm the correct connection diagram (Figures 5, 6 and 7) was used, then check EC-30 wiring connections.
- Confirm that the correct voltages are present on each terminal.
- Check all terminal connections on both ends of the wiring harness and confirm harness connectors are properly joined.
- Repeat the TEST SYSTEM procedure as described in the manual.
Tools required
- Voltmeter Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
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.