Detroit Diesel — Stator Test Procedure
Testing & diagnosis
From a Detroit Diesel service manual — check it applies to your exact model before use.
Before you start
- Hazardous voltage. Operate the generator set only when all guards and electrical enclosures are in place.
Procedure
- Move master switch to OFF/RESET.
- Disconnect starting battery, negative lead first.
- Check alternator output lead connections.
- Disconnect all stator leads to isolate windings; set ohmmeter to R x 1 scale.
- Check stator continuity per Figure 3-16 (three phase) or Figure 3-18 (single phase).
- Zero the ohmmeter; check cold resistance of stator windings (leads 1-2, 3-4, etc.).
- Replace stator if any readings vary.
- Megohmmeter test: apply 500 V DC to any stator lead from each winding and stator frame.
Tools required
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Specs & values
- A reading of 500 kOhms (1/2 megohm) and higher indicates stator is good
Source: Detroit Diesel 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.