Generator - CS-144 Diagnosis and Repair

Bulletin No. T 87-53
File in Group 6D
Number 31
Corp. Ref. No. 716402
Date Dec. '86

SUBJECT: CS-144 GENERATOR DIAGNOSIS AND REPAIR

MODELS AFFECTED: 1986-1987 DE VILLE AND FLEETWOOD 1986-1987 ELDORADO AND SEVILLE

Figure 1:

Some 1986-1987 De Villes, Fleetwoods, Eldorados or Sevilles may experience illumination of the "No Charge" lamp. Illumination of this lamp indicates that the charging system is not operating normally. The following "No Charge" lamp diagnosis procedure is the first step in diagnosing any charging system condition.

"NO CHARGE" LAMP DIAGNOSIS

De Ville/Fleetwood Use the indicator lamp diagnosis chart in Figure 1.

Figure 2:

Eldorado/Seville If the "No Charge" lamp is illuminated with the engine running, check for
BCM trouble codes B410, B411 and B412. If any of these trouble codes are present, follow the respective fault trees in Section 8D of the 1986 Final Edition Service Information Manual. If there are no codes present, go to the CS-144 Generator Functional Check in Figure 2.

If the "No Charge" lamp diagnosis or CS-144 Generator Function Check leads to disassembly, test and reassembly, proceed as follows:

DISASSEMBLY, TEST AND REASSEMBLY

Figure 3 - Generator Checks:

Figure 4 - Generator Checks:

Figure 5 - Generator Assembly:

For generator disassembly, test and reassembly procedures, refer to Figures 3, 4 and 5.

NOTE: Whenever the rectifier bridge and voltage regulator are removed from the slip ring end frame during disassembly and test, the following procedure must be used during reassembly or a NO CHARGE condition will result (see Figure 5).

1. Install rectifier bridge and capacitor to end frame. The capacitor strap has an insulating material on one side which MUST be assembled contacting the end frame bolt hole boss (Figure 5, Item A). Tighten rectifier bridge attaching screws and nut.

2. Install voltage regulator and brush holder to end frame. There should be "metal-to-metal" contact between the capacitor strap and voltage regulator. Tighten the voltage regulator attaching screws.

3. Crimp and solder connections at voltage regulator (avoid excessive heat).
For warranty purposes, use Labor Operation Number J4080 at .8 hour plus any appropriate ADD operation when repairing the generator. When replacing a generator assembly with a remanufactured unit (P/N 10497111), use Labor Operation Number J4100 at .6 hour with the required zone approval.