Cummins/Onan — Field Coil Grounded Circuit Test
Testing & diagnosis · field windings
From a Cummins/Onan service manual covering: 10C, 10CW, 10CW-150R, 5CW, 5TW-0R, 6CW-54R, 7.5C, 7.5CW, 8CW. Check it applies to your exact model before use.
Applies to: Cummins/Onan 10CW, Cummins/Onan 10CW-150R
Procedure
- Connect one test lamp lead to a bare metal part of the generator frame.
- Connect the other test lead to the coil terminal F+.
- If the test lamp lights, a grounded circuit is indicated.
- Remove the screws mounting one pole shoe to the frame.
- Push the pole shoe and coil away from the frame.
- If the ground is eliminated, the grounded coil is isolated.
- Repeat until the grounded coil is located.
- Repair the insulation at the point of damage.
Tools required
- test lamp set Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Cummins/Onan 10CW →, Cummins/Onan 10CW-150R →
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.