Cummins/Onan — Battery Charging Check
Maintenance · Battery charging system
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan HDKA, Cummins/Onan HDKAQ, Cummins/Onan HDKAR
Procedure
- With the engine running, check the DC voltmeter (control option).
- The 12-volt system should read 13.5 to 15 volts.
- If output voltage is high (over 15 volts), replace the alternator (regulator probably shorted).
- Charge circuit is protected by circuit breaker CB13.
Tools required
- DC voltmeter Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 12-volt Amazon eBay $11.99 FridayParts $65.01 system should read 13.5 to 15 volts
Full service-parts list: Cummins/Onan HDKA →, Cummins/Onan HDKAQ →, Cummins/Onan HDKAR →
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.