Illustration 1 | g00524107 |
Junction Box (1) Starting motor magnetic switch (SMMS1) |
The starting motor magnetic switch for the 24 DCV systems is mounted in the junction box. This junction box is located on the side of the generator terminal box. Two switches are used in dual starting motor systems. One switch is used for each starting motor.
Test Procedure
- Disconnect wire 4 from the terminal on the subpanel. The subpanel is located within the control panel. Measure the resistance that is between wire 4 and the battery negative terminal ("B-"). The resistance should measure the following values.
- 26 ohms to 33 ohms for single starting motor systems
- 13 ohms to 17 ohms for dual starting motor systems
If the resistance is NOT correct, replace the old magnetic switch. If the resistance is correct, proceed to Step 2.
- 26 ohms to 33 ohms for single starting motor systems
- Disconnect the cable that goes from the pinion solenoid to the starting motor. Disconnect both cables on a dual starting motor system.
- At the SMMS, connect a DC voltmeter to the two large terminals. The positive lead connects to wire 24 and the negative lead connects to wire 25. (If the second magnetic switch is tested in a dual starting motor system, then connect the negative lead to wire 26.)
Note: The jumper wire of Step 4 should remain connected for only ten seconds.
- Temporarily connect wire 4 to the battery positive terminal ("B+"). Disconnect this wire immediately after the voltage is measured. The wire should not remain connected more than 10 seconds. The correct measurement changes from approximately 24 DCV to approximately 2 DCV.
If the voltage is greater than 2.0 DCV, replace the magnetic switch. If the switch passes the requirements of Step 1 and Step 4, the switch is functioning correctly. Reconnect the wires and cables that were removed in this procedure.