LOCKNUT 8S8874 - Caterpillar

System Operation Description:Switch circuits may have problems such as faulty wiring, faulty switches, or faulty connectors. Use the following diagnostic procedures in order to diagnose problems with these switch circuits and repair these switch circuits:
Diagnostic reset switch
Droop-isochronous switch
Low idle switch
Maintenance clear switch
Remote engine stop switch
Run/stop switchThe switches are normally open or normally closed.
Illustration 1 g01121934
Typical switch inputs
Test Step 1. Check the Electrical Connectors and the Wiring
Place the keyswitch in the OFF position.
Illustration 2 g01146374
Location of the Electronic Control Module (ECM) (typical example)
(1) J1/P1 ECM connectors
Illustration 3 g01146383
Location of the customer connector (typical example)
(2) P61 customer connector
Thoroughly inspect connectors (1) and (2). Thoroughly inspect the connections for the suspect switch. Refer to Troubleshooting, "Electrical Connectors - Inspect".
Illustration 4 g01175187
P1 terminals for the various switches
(P1-22) Maintenance clear switch
(P1-23) Remote engine stop switch
(P1-40) Run/stop switch
(P1-41) Diagnostic reset switch
(P1-46) Droop-isochronous switch
(P1-47) Low idle switch
Illustration 5 g01175207
P61/J61 terminals for the various switches
(19) Run/stop switch
(34) Droop-isochronous switch
(35) Low idle switch
(36) Maintenance clear switch
(37) Diagnostic reset switch
(39) Remote engine stop switch
Perform a 45 N (10 lb) pull test on each of the wires in