Cummins/Onan — Two to Three Wire Start Conversion (12 Volts)
Adjustments · Control accessory panel 2 to 3 wire converter
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Before you start
- Failure to remove AC power from the automatic transfer switch and to disable the generator set presents a serious shock hazard during this modification.
Procedure
- Move the operation selector switch on the engine control to STOP.
- Disconnect the starting batteries.
- Remove AC line voltage from the automatic transfer switch.
- Open the automatic transfer switch cabinet door.
- Remove the remote start wire leads between the engine control remote terminal block and the automatic transfer switch terminal block TB1.
- Remove the 300-0937 blank (spare) module 9 and replace with a 300-0926 2 to 3 wire converter module.
- Check battery voltage (battery must be a 12-volt unit). If DC system was 24 volts, make the DC system voltage conversion first.
- Connect automatic transfer switch terminals TB1-B+, -1, and -3 to the three-wire start engine control.
- Restore AC line voltage to the automatic transfer switch.
- Connect the starting batteries.
- Move the operation selector switch on the 2 to 3 wire converter module 9 to NORMAL.
- Close the cabinet door.
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.