All Models

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 has about 90 ohms resistance when oil pressure is high. A change in resistance changes current flow through gauge electromagnetic coils, causing pointer to move from low to high. Sending unit locations are as follows.

• 2.5L - In right side of block, under intake manifold.
• 2.8L - At bottom left of engine block, on oil filter housing.
• 4.3L (Astro, Safari, S and T Series) - At top rear of engine block.
• 4.3L (All Others) - At lower left rear of engine block.
• 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.