GEAR-WATER PUMP 7N5306 - Caterpillar

Introduction
This special instruction covers testing of the upper limiter switch and lower limiter switch with the proper diagnostic of the wiper motor and wiper controller. Before replacing 328-0651 Wiper Control Gp , check for proper functioning of the window switches. Do not perform any of the procedures until you have read the information in this publication.Safety
Do not operate or work on this machine unless you have read and understand the instructions and warnings in the Operation and Maintenance Manuals. Failure to follow the instructions or heed the warnings could result in injury or death. Contact your Caterpillar dealer for replacement manuals. Proper care is your responsibility.
Troubleshooting Procedure
In order to prevent an incorrect diagnostic on the wiper motor or wiper controller on certain Medium and Large Hydraulic Excavators that are equipped with front sliding windows, the following troubleshooting procedure can be undertaken to check for proper window limiter switch function.Check both the upper and lower limiter switches function adjustments.Note: The switches are normally open switches.
Illustration 1 g03601110
Cab area (A) View of area (B) View of area (1) Upper limiter switch (2) Lower limiter switch
Adjust both switches so that they are in a closed state when both windows are installed and closed. In such a condition, a ground signal is sent to the wiper controller, A584 Pin 1, and the controller is sending the appropriate wiping signal depending on the wiper switch position.
Tilt open the upper window so the upper limiter switch and the wiper controller, A584, becomes an open circuit. In proper working condition, the controller will finish the current wiping cycle and park the wiper arm, preventing a new wiping cycle.
Remove the lower window by lifting it and closing the upper window. A new wiping cycle will not be generated because the lower limiter switch and wiper controller, A584, circuit will be open. No ground signal will be present.
Tilt open the upper window, reinstall the lower window, and close the upper window. With both windows closed, both limiter switches are back in a closed state. A ground signal is sent to the wiper controller, A584. A wiper switch command will generate a wiping cycle.Note: In most cases, the upper and lower limiter switch thread length allows for proper adjustment without replacement. In a few cases where the thread length does not provide enough adjustment, refer to Special Instruction, REHS7514, "Diagnostic Procedure for the Wiper Motor and Wiper Controller Malfunction on Certain Excavators that are Equipped with Front Sliding Windows".
Illustration 2 g03604097
Electrical schematic (1) Upper limiter switch (2) Lower limiter switch (3) Wiper controller (4) Wiper motor (5) Washer pump (6) Switch panel