CLAMP 1549159 - Caterpillar

the negative test lead to wire "110C-GY" on the voltage/frequency converter in order to verify that 24 DCV is present.
Move the positive test lead to wire "111-RD" on the voltage/frequency converter.
The negative test lead remains connected to wire "110C-GY". Verify that the input voltage for the voltage/frequency converter is 5 1 mV. This voltage matches the output voltage for the current transducer. The voltage is 5 1 mV for both readings.
Set the Digital Multimeter on the scale for frequency ("Hz").
Connect the positive test lead to wire "112-PK" on the voltage/frequency converter.
The negative test lead remains connected to wire "110C-GY".
Read the output frequency of the voltage/frequency converter.Expected Result:The frequency is 60 5 Hz. Results:
YES - The frequency is 60 5 Hz. The frequency is correct. Proceed to Test Step 21.
NO - The frequency is not 60 5 Hz. The voltage/frequency converter has failed. Repair: Replace the voltage/frequency converter. STOPTest Step 21. DROP SOLID STATE RELAY TESTNote: See Electrical Schematic, RENR3125.
Set the Digital Multimeter on the "AUTO" setting or set the multimeter on the "40 DCV" scale.
Connect the positive test lead to terminal "101C".
Connect the negative test lead to terminal "102D".
Start the engine and run the engine at high idle.
Verify that the magnet/grapple switch is in the magnet position.
Depress the lift switch in the right-hand joystick.
After 3 seconds, depress the drop switch. The drop switch is located in the left-hand controller. Observe the multimeter. Expected Result:The multimeter reads approximately 28 DCV when the terminal "101C" is positive during the lift cycle. The multimeter reads approximately, negative 28 DCV when the terminal "101C" is negative during the drop cycle. Results:
YES - The multimeter reads approximately 28 DCV when the terminal "101C" is positive during the lift cycle. The multimeter reads approximately, negative 28 DCV when the terminal "101C" is negative during the drop cycle. The drop solid-state relays are functioning properly. Proceed to Test Step 24.
NO - The multimeter reads approximately 28 DCV when the terminal "101C" is positive during the lift cycle. The multimeter does NOT read a negative voltage during the drop cycle. The solid-state relay ("SSR172") may have failed. Also, The solid-state relay ("SSR173") may have failed. Proceed to Test Step 22 in order to determine the relay that has failed.Test Step 22. TEST FOR THE DROP SOLID STATE RELAY (SSR172).Note: Refer to the electrical system schematic Schematic, RENR3125.
Connect the positive test lead to terminal "102D".
Connect the negative test lead to terminal "102C".
Press the lift switch in the right-hand controller.
Wait for 3 seconds. Then press the drop switch in the left-hand controller. Observe the voltmeter while you perform this Test Step. Expected Result:The meter indicates zero DCV during lift. The meter indicates approximately 28 DCV with the positive terminal "102D" during the drop.Results:
YES - The meter indicates zero DCV during lift. The meter indicates approximately 28 DCV with the positive terminal "102D" during the drop. The relay is functioning properly. Proceed to Test Step 23.
NO - The meter indicates zero DCV during Lift