Circuit/System Description

The Body Control Module (BCM) monitors the control circuit of the WIPER relay. The voltage level should be low while the WIPER relay is de-energized and near system voltage when the relay is energized. After the BCM receives a low, intermittent, or mist signal from the wiper/washer switch, it responds by applying battery voltage through the WIPER relay control circuit to the coil side of the relay, energizing the WIPER relay.