MOTOR GP-PISTON 0R4189 - Caterpillar

A. The lift lever is not held in the RAISE position.For the lift lever to be held in the RAISE position: Connect a jumper wire across the oil pressure switch.1. Check for power to the solid state switch. a. Disconnect the P/W wire from the connection on the solid state switch marked FUSE.b. Check this wire for machine voltage with a 5P7277 Voltage Tester. Connect the clip of the tester to the wire connector and touch the point to machine ground. 2. Check for correct operation of the solid state switch. a. Disconnect the P/DK BL wire from the connection on the solid state switch marked SWITCH.b. Pull the bullet connectors apart a small amount, on the harnesses between the solid state switch and the electromagnet.c. Fasten the clip of the 5P7277 Voltage Tester to machine ground and touch the point of the tester to the pin connection of the solid state switch plug. There must be voltage. d. Put a jumper wire from the connection marked SWITCH on the solid state switch to machine ground.e. Again put the point of the tester to the pin connection of the solid state switch plug. There must not be voltage. 3. Check for continuity through the electromagnet. a. Disconnect the solid state switch harness plug from the electromagnet harness plug.b. Check for continuity between the pin and receptacle in the electromagnet harness plug. There must be continuity. 4. The solid state switch and the electromagnet work correctly. The problem must be either in the alignment of the electromagnet and the plates of the lever, or in the external control circuit for the solid state switch. Check for the alignment of the electromagnet and plates.a. Put a jumper wire from the connection marked SWITCH on the solid state switch, to machine ground.b. Move the lever to the RAISE position. The lever must stay in the RAISE position. 5. Adjust the position of the magnet or change the length of the linkage rod so that the plate on the lift lever is in complete contact with the electromagnet.6. With the lift lever in the RAISE position and the bucket in a position lower than the kickout position, the external control circuit at the SWITCH n connection on the solid state switch must be continuous to ground. Check for an open in the circuit. a. Disconnect the P/DK GR wire from the O wire of the lift lever switch (6).b. Check for continuity to ground at the O switch wire. c. Disconnect the P/DK GR wire from the DK GR wire of the lift lever switch (6).d. Check for continuity at the P/DK GR wire to machine ground. e. With the continuity tester connected to the two leads from the lift lever switch, move the lever so that magnet (7) goes close to the switch. The magnet must be adjusted so that it moves close to the switch. The switch must be closed (have continuity) with the lever in the RAISE position.f.