RETAINER 6G2777 - Caterpillar

Illustration 14 g06171682
(F) Exciter-Stator (field) leads and ring terminals
(G) MS Connector leads and ring-terminals
If the Exciter-Stator (field) (F) insulation resistance is less than 50 mega-ohms or winding resistance is greater than 1 ohm when measured at the MS connector pins (G), remove the Auxiliary-Box cover.
If the Exciter-Stator (field) insulation resistance is less than 50 mega-ohms, disconnect the Exciter-Stator (field) lead ring-terminals from the terminals-strip. connect the positive lead of the "Insulation Resistance Tester" to both ring-terminals for the Exciter-Stator (field). connect the negative lead of the "Insulation Resistance Tester" to a ground boss or other stator grounding point. Measure insulation resistance of the Exciter-Stator (field) at 500 V. The insulation resistance (1 min) should be greater than 50 mega-ohms.
Illustration 15 g06171698
View of the MS connectors
If the Exciter-Stator (field) winding resistance is greater than 1 ohm at the MS connector pins, inspect the leads and ring terminals for the Exciter-Stator (field) and MS connector marked "EF1" and "EF2". Check the ring-terminal connections at the terminal-strip are tight. Disconnect the Exciter-Stator (field) lead ring-terminals from the terminal-strip. Measure the winding resistance of the Exciter-Stator (field) across the lead ring-terminals. The resistance should be approximately 1 ohm. Inspect the ring-terminals and verify that the heat-shrink does not interfere with the ring-terminal making good contact with the terminal-strip. (Refer to Illustration 16.)
Illustration 16 g03856617
Illustration 17 g06171702
Location of the Auxiliary-Box with the cover in place
If insulation resistance and winding resistance of the Exciter-Stator (field) is within spec when checked at the lead ring-terminals, check the continuity of the MS connector and leads from pin to ring-terminal. Check insulation resistance of the MS connector and wiring harness assembly can be replaced with a new 449-7673 Wiring Harness.
If insulation resistance of the Exciter-Stator (field) insulation resistance is less than 50 mega-ohms or the winding resistance is greater than 1 ohm when checked at the lead ring-terminals in the auxiliary enclosure, call the Cat® help line, "CALL DSN", for support.Replacing the Generator Rotating Diodes
Illustration 18 g06168314
Diode connection points on the rotating plates
(1) 1/4-20 inch nut used to secure the diode flying leads to the rotating plates
(2) 3/8-24 inch nut and washer that is used to fasten the base lead of the diode to the rotating plateIF ANY ONE DIODE IS FOUND TO BE FAULTY, REPLACE ALL SIX OF THE ROTATING DIODES. The diodes must be replaced as a set of six. When one diode fails, the failure will cause the other diodes to be stressed.When replacing the set of six diodes, disconnect and remove one diode at a time. Ensure that the diode is replaced with a new diode. The new diode must have the same part number, the same base lead polarity, and the same flying lead color.When installing the new diode on the assembly, use the following torque specifications for tightening the nuts:
1/4-20 inch nut (15) ............. 8.1 1.4 N m (72.0 12.0 lb in)
3/8-24 inch nut (24) ............. 13.6 2.7 N m (120.0 24.0 lb in)Follow this procedure to replace the diodes.Note: Before