Cummins/Onan — Voltage Regulator (VR21) Replacement [O]
Repair & overhaul · Voltage regulator printed circuit board VR21
From a Cummins/Onan service manual — check it applies to your exact model before use.
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Before you start
- Do not replace the printed circuit board until the trouble not on the PC board has been located and corrected to avoid damage to new PC board.
Procedure
- Stop engine.
- Disconnect and if necessary label wires 3, 4, 5 or 6, 7, 8, 9, and 10.
- Remove four screws at corners.
- Remove used PC board.
- Install new PC board; secure with four screws.
- Reconnect wires removed in step 2 at the proper terminals.
- Place jumper W10 at proper terminals for your voltage code and voltage connection.
- Perform Voltage Calibration and Stability Adjustment procedures [A] and [B].
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.