Vacuum Harness HVAC: Testing and Inspection

Typical Vacuum Control System For Illustrative Purpose:

System Check Overall
1. First check that vacuum hoses are connected correctly.
2. Connect vacuum-gauge as shown, place gauge so-it can be read from inside car.
3. Remove glove box or radio.
4. Remove control assembly cover plate.
5. Start engine, increase engine speed until vacuum gauge reads approximately 15 in. Hg.
6. Move air distribution lever and temperature control lever together to extreme rght stop.





7. Stop engine. Note gauge reading. After one-minute check gauge reading and compare with chart (ref. image).