Vacuum Motor Test
- With engine not running, air cleaner may be removed for this test. Disconnect vacuum hose from vacuum motor.
- Connect an external vacuum pump to vacuum motor. Apply specified vacuum for "Door Fully Closed". See Air Control Door Opening Vacuum specifications table .Vacuum Control Temperature Sensor Specifications
Application Air Door Closing Temp. (°F) Air Door Opening Temp. (°F) American Motors 40 55 Chrysler 1.7L & 2.2L 50 85 2.6L 85 113 All Other Models 50 100 Ford Motor Co. Sensor Color Code Brown 75 75 Black or Pink 75 90 Blue or Yellow 75 105 General Motors Corp. Buick 77 (1)123 Cadillac 85 105 Chevrolet Citation 77 (1)123 All Other Models 80 (1)100 Oldsmobile 77 (1)123 Pontiac 77 (1)123 (1) ± 20°F. - Air control door should remain closed to outside air (open to heated air from shroud around exhaust manifold).
- Next, apply specified vacuum for Door Fully Open In. Hg, see Air Control Door Opening Vacuum specifications table . Air control door should open to outside air (closed to heated air).
- Apply 20 in. Hg to vacuum motor and pinch off hose. Vacuum should not leak down more than 10 in. Hg in 5 minutes. If vacuum motor fails any of these checks, replace it.Air Control Door Opening Vacuum
Application (1) Door Fully Closed Less Than In. Hg (2) Door Fully Open Max. In. Hg Chrysler Corp. 4-Cylinder Models 2 4 All Other Models 5.5 8.5 American Motors 4-Cylinder 7 6-Cylinder 4 Ford Motor Co. General Motors Corp. Buick 7 Cadillac 4-6 (3) Chevrolet 7 Oldsmobile 7 Pontiac 7 (1) Closed to outside air (heated air position). (2) Closed to heated air (outside air position). (3) Manifold vacuum.