ROTOCOIL AS 1977063 - Caterpillar

Illustration 1 g00482547
Magnetic Switches On Subpanel(Two Switches That Are Shown Are For The System With Two Starting Motors.)The starting motor magnetic switch (SMMS) for the 24 DCV systems is mounted on the subpanel within the control panel. Two switches are used in a system with two starting motors. One switch is used for each starting motor.Test Procedure
Disconnect the jumper wire between terminals TS1-4 and TS1-5 in the generator housing. Measure the resistance between terminals TS1-5 and TS1-2.
The resistance should measure 26 to 33 ohms for the systems with one starting motor.
The resistance should measure 13 to 17 ohms for the systems with two starting motors.If resistance is NOT correct, replace the defective magnetic switch. If the resistance is correct, proceed to step 2.
Disconnect the cable that is going from the pinion solenoid to the starting motor. Do this procedure on both starting motors of a system with two starting motors.
Connect a DC voltmeter. Connect the positive cable to terminal TS1-24 and the negative cable to terminal TS1-25 in the generator housing. (If the second magnetic switch is tested in a system with two starting motors, then connect the negative cable to terminal TS1-26.)Note: The jumper wire of step 4 can remain connected for only ten seconds.
Connect a jumper wire from terminal TS1-1 to terminal TS1-5 in the generator housing. Disconnect this wire immediately after the voltage is measured. Do not leave the wire on more than 10 seconds. The correct measurement changes from approximately 24 DCV to approximately 2 DCV.If voltage is greater than 2.0 DCV, then replace the magnetic switch. If the switch passes the requirements of step 1 and 4, the switch is functioning correctly. Reconnect the wires and cables that were removed in this procedure.