Wiper Motor

The wiper motor is controlled by the CJB. The CJB is connected to a wiper motor normal/fast relay in the EJB on 2 wires. The CJB is also connected to a wiper run/park relay, also located in the EJB.

Driver requests are received by the CJB which energizes the wiper motor normal/fast relay in the appropriate mode (normal or fast wipe) and also energizes the run/park relay in the run mode by providing a ground for the relay coils. When wiper operation is deselected by the driver, the CJB monitors a park switch which is integral with the wiper motor. On receipt of a signal from the park switch, the CJB de-energizes the run/park relay, removing the power supply through the normal/fast relay, stopping the wipers in the park position on the windshield.

The wiper motor is a DC (direct current) motor which drives a gear wheel via a worm drive attached to the motor spindle. The motor has 3 sets of brushes with one brush connected to ground. When the normal/fast relay is energized in the normal position, a power feed is supplied to the brush directly opposite the ground brush and operates the motor at slow speed. When the relay is energized in the fast position, a power feed is connected to the second motor brush, which is offset from the ground brush and operates the motor at the fast speed. With power supplied through the offset brush, the current flows through fewer motor coil windings. This results in a lower resistance to current flow to the ground brush and produces a higher motor rotational speed.