Facts About Generators
GeneratorsDirectoryCompareRepairEnginesControllersPartsManufacturersGuides
Search models or part #
Home›Repair guides›Detroit Diesel›Generator Rotor Test Procedure

Detroit Diesel — Generator Rotor Test Procedure

Testing & diagnosis · Rotor main field

From a Detroit Diesel service manual — check it applies to your exact model before use.

Procedure

  1. Disassemble alternator; disconnect rotor main field from RRA terminals F+ and F--.
  2. Check rotor main field resistance across F+ and F-- with an ohmmeter.
  3. Megohmmeter test: apply 500 V DC to either rotor main field lead and main field frame; replace with less than 500 kOhms.

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 rotor main field 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.

More Detroit Diesel repair guides →