Relay Coil
WARNING: This page is about a different car, the 1988 Buick Riviera and 1988 Buick Reatta. However, it is still accessible from the selected car via links, so may be relevant.
Pump/motor relay coil is powered by circuit No. 250 through a 5-amp pump/relay fuse, located under dash. Circuit No. 864 runs from ground side of relay coil to pin "A" of pressure switch. Pressure switch is normally open. When accumulator pressure drops to 2030 psi (14,000 kPa), pressure switch closes, grounding pump/motor relay coil.