Auxiliary Vacuum Circuit Test Procedure: Notes
Remove car vacuum harness plug from programmer valve, which should direct all airflow to floor except for defroster bleed air. Connect tee with short hose and union to J-23678 tester vacuum gauge hose as shown in sketch at right, inserting tee in Part No. 2 of harness plug and probing each of the other ports in turn. Make sure that control head lever is set as specified for each step, and cover up probe on Ports 3 and 9 when called for, to seal off other circuit branches. For each step, full vacuum should be read after actuator-travel is completed.
| Control Lever | Probe Port: | Hose Color | Cover up | Other Hoses In Circuit | Action Expected |
|---|---|---|---|---|---|
| Bi-Level | None | Black | Probe | Yellow | Defroster door moves to "bleed" position |
| Bi-Level | 1 | White | None | None | Hot water valve closes - Check air in "max. heat" |
| Bi-Level | 3 | Red | Port 9 | Purple, Tan | Lower mode door moves to A/C position |
| Bi-Level | 4 | Orange | None | None | Recirc door opens - 1-2 min. delay |
| Lo | 5 | Chartreuse | Port 9 | Purple | Checks control head vacuum leakage |
| Lo | 6 or 8 | Green | None | None | Upper mode door moves to A/C position |
| Hi | 7 | Dark Brown | None | Tan | Lower mode door moves to A/C position |
| Def | 9 | Purple | Port 3 | Red, Dk. Blue | Defroster door moves to full "DEF" position |
A low vacuum reading in any step indicates a leak in control head valve or in the hoses and components listed in that step. If some function is missing even though full vacuum is available, reconnect harness plug to programmer and check vacuum at extreme end of hoses involved, to distinguish between a pinched hose and a mechanical bind in actuator or door.