Cummins/Onan A15 — Testing the Float Switch Assembly
Testing & diagnosis · fuel transfer pump day tank
For the Cummins/Onan A15, from the Cummins/Onan service manual.
Applies to: Cummins/Onan DGBB, Cummins/Onan DGBC, Cummins/Onan DGCA, Cummins/Onan DGCB, Cummins/Onan DGCC, Cummins/Onan DGDA, Cummins/Onan DGDB, Cummins/Onan DGEA, Cummins/Onan DGFA, Cummins/Onan DGFB, Cummins/Onan B and C Series diesel engine
Procedure
- Remove fuel pump control cover, disconnect wiring jack, unscrew assembly from top of day tank.
- Test electrical continuity between each pair of colored leads while holding assembly vertical (should read zero/closed).
- Lift each float to 1/8 inch (3mm) below C-clip stop and test continuity (should read infinity/open).
- Use pipe thread sealant when replacing assembly.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- 1/8 inch (3 mm) below C-clip stop
Full service-parts list: Cummins/Onan DGBB →, Cummins/Onan DGBC →, Cummins/Onan DGCA →, Cummins/Onan DGCB →, Cummins/Onan DGCC →, Cummins/Onan DGDA →, Cummins/Onan DGDB →, Cummins/Onan DGEA →, Cummins/Onan DGFA →, Cummins/Onan DGFB →
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.