CS144 (Without Auxiliary Phase Terminals)

1. Scribe end frames to facilitate reassembly. Remove through-bolts and separate end frames.
2. With ohmmeter set to its lowest range, measure coil resistance between slip rings. See Fig 1 . Replace rotor if coil resistance is not 2.1-2.4 ohms at 70°F (21°C).
3. With ohmmeter set to its highest range, check for grounds between either slip ring and rotor pole piece. See Fig 1 . If reading is not close to infinite, replace rotor.
4. To reassemble alternator, reverse disassembly procedure. Retain brushes with brush retaining pin during reassembly. See Fig 2 . Remove retaining pin after tightening through-bolts.

Fig 1: Testing Alternator Rotor (CS144)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Removing Brushes (CS144)

Courtesy of GENERAL MOTORS CORP.