Over-Volage Protection Relay
ABS system power is provided through the Over-Voltage Protection Relay (OVPR). This relay includes a special diode arrangement which will interrupt power to the Anti-Lock Brake System (ABS) in the event of excessively high system voltage. This relay will cause the 20 amp brake fuse (fuse No. 1 in the maxi fuse panel) to blow if high system voltages are encountered. Should an over-voltage situation occur, the relay will not be damaged and can be used again.
The OVPR coil is powered through the 7.5 amp in-line brake fuse, located under the dash near the Electronic Brake Control Module (EBCM) connector. The relay coil is provided both power and ground whenever the ignition is in the run position, meaning that the system should be receiving power anytime the ignition is on. See Fig 1 .
Circuit 850 distributes power to the ABS when the relay contacts are closed. Components which receive power from this circuit include, EBCM Pin 1, Sensor Block - Pins 3 and 4, and pump relay connector (for relay coil) - Pin 4. See CONNECTOR FACES . Circuit 850 is provided battery voltage through the 20 amp brake fuse in the rear fuse panel.