Oil Pressure Gauge
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 1991 GMC Pickup, 1991 GMC Cab & Chassis, 1991 GMC C3500 HD, 1991 Chevrolet Pickup, and 1991 Chevrolet Cab & Chassis. However, it is still accessible from the selected car via links, so may be relevant.
Oil pressure gauge measures electrical current from variable resistance unit (oil pressure sending unit). Sending unit has low resistance when oil pressure is low and about 90 ohms resistance when oil pressure is high. A change in resistance changes current flow through gauge electromagnetic coils, moving pointer toward appropriate reading.
Sending unit locations are as follows:
- 4.3L, 5.0L & 5.7L At lower left rear of engine block.
- 6.2L At top left rear of engine block.
- 7.4L At lower left front of engine block.