Cummins/Onan — Replacing Rectifiers (Diodes)
Repair & overhaul · Rotating rectifier assembly
From a Cummins/Onan service manual — check it applies to your exact model before use.
Applies to: Cummins/Onan DFM
Before you start
- Use a 40 watt soldering iron; hold needlenose pliers between rectifier and soldering point to prevent destructive heating
Procedure
- Unsolder leadwires from terminals
- Use proper size wrenches to hold the body while removing the nut
- Push the rectifier free of its mounting hole in the heat sink
- Insert new rectifier into its mounting hole and secure with nut and washer
- Torque diodes on rotating exciter assembly to 15 lb. in. (1.7 N.m)
- Solder leadwires to new rectifiers
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- Torque diodes to 15 lb. in. (1.7 N.m)
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.