GEAR ASSEM. (27 T.) 5F8698 - Caterpillar

Machines So EquippedAll wiper motors are grounded through the motor mounting to the cab or door of the machine. On some models, the cabs are painted before assembly to keep rust from forming. Paint, rust or a loose motor mounting can cause a wiper motor to operate slower than normal. In some cases, the motor may not operate at all.
Always check the motor ground as part of a wiper motor troubleshooting or replacement procedure. A 6V7070 Multimeter or equivalent can be used to verify the condition of the motor ground. Place the multimeter selector switch on the "DC-200 Volt" position. With the wiper motor running (if the wiper motor does not operate, place the wiper motor switch in the "ON" position), connect the multimeter between the motor case and a good ground on the frame. The reading on the multimeter should be less than 0.6 volts (0.3 volts on a 12 volt system). A voltage reading above this value indicates a poor ground connection.