Cummins/Onan — AC voltage regulator replacement
Repair & overhaul
From a Cummins/Onan service manual covering: 4A2.3, 6A3.4-GS, 6AT3.4-GS, DL4, DL6, QSA3, QSA4, QSA6. Check it applies to your exact model before use.
Applies to: Cummins/Onan DGAB, Cummins/Onan DGAC, Cummins/Onan DGAD, Cummins/Onan DGAE, Cummins/Onan DL4, Cummins/Onan DL6
Before you start
- Accidental starting can cause severe injury or death; disconnect battery.
Procedure
- Stop genset and disconnect starting battery leads, negative lead first.
- Disconnect and label wires from voltage regulator TB1.
- Remove mounting screws from old regulator and install new regulator.
- Reconnect wires removed in previous step to proper terminals.
- Perform voltage regulator adjustment and switch settings for desired voltage and regulation mode.
Tools required
- Screwdriver Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Cummins/Onan DGAB →, Cummins/Onan DGAC →, Cummins/Onan DGAD →, Cummins/Onan DGAE →, 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.