Rectifier Bridge - Cs144 Only

Scribe end frames to facilitate reassembly. Remove through-bolts and separate end frames. Connect an ohmmeter from grounded heat sink to one (of the 3) grounded flat metal rectifier bridge terminal connectors and note reading. See Fig 1 .

Fig 1: CS144 Alternator Rectifier Bridge Test
Courtesy of GENERAL MOTORS CORP.
Reverse leads. If both readings are the same, replace rectifier bridge. Repeat test between grounded heat sink and the other 2 flat metal terminal connectors. If reading is the same when leads are reversed at either connection, replace rectifier bridge.
Repeat test between insulated heat sink and its 3 flat rectifier bridge metal connectors. Replace rectifier bridge if test reading is the same when leads are reversed at any test connection.
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 2: CS144 Brush Removal

Courtesy of GENERAL MOTORS CORP.

NOTE: Manufacturer recommends using a new bearing whenever end frames are separated.