Cummins/Onan 6.5NH - 3CR / 6000 A — Armature Short Circuit Test (Growler)
Testing & diagnosis
For the Cummins/Onan 6.5NH - 3CR / 6000 A, from the Cummins/Onan service manual.
Applies to: Cummins/Onan NH engine
Procedure
- Place the armature in a growler.
- With the growler current on, hold a steel strip about 1/2 inch above the armature laminations.
- Pass the strip back and forth over the laminations, covering as much area as possible.
- If the strip is magnetically attracted at any point, a short circuit is indicated.
- Rotate the armature slightly in the growler and repeat until a complete revolution has been made.
- Replace a short circuited armature with a new one.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
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.