Cummins/Onan — Testing Exciter Stator (Test H)
Testing & diagnosis
From a Cummins/Onan service manual covering: DL4, DL6, DL6T. Check it applies to your exact model before use.
Applies to: Cummins/Onan DL4, Cummins/Onan DL6, Cummins/Onan DL6T
Procedure
- Disconnect F1+ and F2- exciter field leads from terminal block in generator end bell.
- Measure resistance between field leads; should be 13.05 to 15.95 ohms at 77 deg F (25 deg C).
- Connect ohmmeter between either field lead and exciter stator laminations on highest range; resistance must be one megohm or greater.
Tools required
- ohmmeter Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 13.05 to 15.95 ohms at 77 deg F (25 deg C)
- 1 megohm or greater to ground
Full service-parts list: Cummins/Onan DL6 →
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.