Wiper Motor: Testing and Inspection

NOTE: These instructions apply to both windscreen and tailgate glass wiper motors.

If unsatisfactory operation of the wiping equipment is experienced, a systematic check to determine the origin of the fault should be carried out as follows:

1. Check the blades for signs of excessive friction, as this will greatly reduce the wiping speed of the motor and cause increased current draw which may damage the armature.
- Check by substitution.

2. Check the windscreen wiper motor light running current and speed with the motor coupling link disconnected from the wiper shaft transmission linkage.
- Check the tailgate glass wiper motor with the wiper connected and the glass wet.
- Connect a suitable analog or digital ammeter in series with the motor supply and measure the current consumption when the motor is switched on.
- Check the operating speed by timing the speed of rotation of the motor coupling link.

NOTE: If the vehicle wiring connections are disconnected and an alternative supply source is applied, it is essential that the correct polarity is observed. Failure to observe this will cause the motor to rotate in the reverse direction, which may result in the limit switch contacts being damaged.

3. If the motor does not run satisfactorily or takes higher than normal current, then a fault is apparent and should be investigated.
4. If the current consumption and speed of the motor are satisfactory, then a check should be carried out for proper functioning of the transmission linkage and wiper arm shafts.

NOTE: Service parts are not available for the windscreen and tailgate wiper motors with the exception of the windscreen wiper rotary connecting link. A complete new unit must be fitted in the event of a failure.