Vacuum Control Temperature Sensor Test
- Tape a thermometer close to the vacuum control temperature sensor, located inside the air cleaner. Leave wing nuts off of top of air cleaner so top can be removed quickly to check thermometer while performing tests.
- With a cold engine, temperature below vacuum control temperature sensor specifications, check air control door in air cleaner. It should be in the fully open position (open to outside air).
- Start engine and let run. As soon as engine starts, door should go to full heated air position (closed to outside air). Watch air control door. When door reaches full open position (outside air only), quickly take air cleaner top off and read thermometer. Compare thermometer reading with specifications. If reading is not to specifications, perform vacuum motor test before replacing sensor.Vacuum Control Temperature Sensor Specifications
Application Air Door Closing Temp. (°F) Air Door Opening Temp. (°F) American Motors 151" 4-Cyl. 77 (1)123 258"6-Cyl. 40 80 Buick(3) Skylark 77 (1)123 All Others 85 (1)115 Cadillac 252" V6 85 115 All Others 85 (2)100 Chevrolet(3) Chevette 80 (1)100 Citation 77 (1)123 All Others 80 (1)100 Chrysler Corp. 1.7L 4-Cyl. 50 85 All Others 50 100 Ford Motor Co. Sensor Color Code Brown 60 90 Black or Pink 60 100 Blue or Yellow 60 115 Oldsmobile 151" 4-Cyl.(3) 77 123 231" V6 79 131 305" V8 79 131 All Others 86 131 Pontiac(3) Phoenix 77 123 All Others 79 123 (1) (1) - ±20°F. (2) (2) - All except Electronic Fuel Injection Models. (3) (3) - Some General Motors 151" 4-Cyl. engines do not use a vacuum motor on air control door. Door is controlled by thermostatic spring only. At 50°F, door is open to heated air only. At 110°F door is open to outside air only.