Cummins/Onan — Testing Field Voltage [A]
Testing & diagnosis · Voltage regulator / brush holder
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan HDKA, Cummins/Onan HDKAQ, Cummins/Onan HDKAR
Before you start
- Disconnect starting battery negative (-) cable before handling electrical wiring or components.
Procedure
- Test field voltage at the brush holder terminals with a DC voltmeter.
- Field voltage should fall between 18 and 60 volts.
- Test at no load and at full load.
Tools required
- DC voltmeter Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Field voltage 18 to 60 volts
Full service-parts list: Cummins/Onan HDKA →, Cummins/Onan HDKAQ →, Cummins/Onan HDKAR →
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.