Cummins/Onan — Solenoid Check
Testing & diagnosis · Start/fuel solenoid
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan MDKC, Cummins/Onan MDKD, Cummins/Onan RGA-OP'
Procedure
- Apply battery positive (B+) to the terminal marked S.
- Connect a ground wire to the solenoid mounting bracket.
- Solenoid should activate.
- Battery voltage should be read between terminal 1 and ground if contacts good.
- Voltage drop across contacts should never exceed one volt.
Tools required
- Voltmeter Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Voltage drop across contacts never exceed one volt.
Full service-parts list: Cummins/Onan MDKC →, Cummins/Onan MDKD →, Cummins/Onan RGA-OP' →
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.