Caterpillar 3516C / 3516C Generator Set — Testing a Brushless Exciter Rotating Rectifier With An Ohmmeter
Testing & diagnosis
For the Caterpillar 3516C / 3516C Generator Set, from the Caterpillar operator's manual.
Applies to: Caterpillar 3516C, Caterpillar 3516C engine
Before you start
- Replace any faulty rectifiers with rectifiers that have comparable operating characteristics
Procedure
- Remove the cover from the exciter.
- Remove the nut that secures the rectifier to the heat sink.
- Remove the diode lead.
- Lift the rectifier from the heat sink.
- Connect ohmmeter leads across the rectifier; note reading.
- Reverse the ohmmeter leads; note reading.
- Low resistance one direction and high resistance reversed indicates good rectifier.
- Low resistance both directions is shorted; high resistance both directions is open.
Tools required
- 237-5130 Digital Multimeter Amazon
- 257-9140 Multimeter Amazon
- 146-4080 Digital Multimeter (RS-232) Amazon
- 7X-1710 Multimeter Probe Group Amazon
Tool links are Amazon searches (affiliate links); manufacturer special tools may only be available from a dealer.
Full service-parts list: Caterpillar 3516C →, Caterpillar 3516C engine →
Source: Caterpillar operator's 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.