Push Button Control Panel Test
- Disconnect engine vacuum source. Apply 8 in. Hg and block test probe. Insert vacuum tester probe in hose leading to control switch. Push HEAT button and observe vacuum gauge reading. Reading should drop during actuator movement. See Fig 1.
- Repeat test on OFF, BI-LEVEL, DEFROST and HEAT buttons, allowing time for actuators to move and vacuum to stabilize. Vacuum will drop below 8 in. Hg after each operation. Maximum allowable drop is 3/4 in. Hg.
- By-pass vacuum reservoir (if equipped). If vacuum drops more than 3/4 in. Hg, inspect 7-port hose connector plug on heater control switch. If necessary, tighten 7-port connector plug. If vacuum drop is now within limits, go to step 6).NOTE: DO NOT use lubricant on switch ports or holes in plug as damage to vacuum valve in switch may result. A drop of water may be used on connector plug holes to help position plug on switch ports.
- If vacuum still drops over 3/4 in. Hg, remove 7-port connector from switch, and seal port No. 3 using finger to block source hose. Insert vacuum source alternately into each connector hole except No. 3.
- If vacuum gauge returns to 8 in. Hg after each actuator has operated, control is leaking and must be replaced. If excessive vacuum drop occurs at one or more holes in connector block, isolate faulty hose or actuator.
- Check engine vacuum lines for leaks. Repair leaks in vacuum lines by cutting out leaking section and installing ends of tube into section of 1/8" inside diameter rubber hose.