Vacuum/Pressure Pump: Description and Operation

CAUTION: The longer nipple on the switch (located at the center of the switch body) should always be connected to the hose leading to the lumbar support. The shorter nipple on the switch body connects to the air pump outlet. If this order is reversed, the lumbar bag will not hold air pressure.

The lumbar support system consists of these components:
- Lumbar seat control switch.
- Front seat back pad adjuster.
- Front seat back pad adjusting pump.
- Seat back control wiring.
- Front seat back pad adjusting tube.

Except for the front seat back pad adjuster, located beneath the seat, all components are generally located at or under the seat back.

The lumbar system operates as follows:
- During the inflate mode, the front seat back pad adjusting pump pumps air through a front seat back pad adjusting tube to the pad adjuster seat control switch.
- Air is then routed through a front seat back pad adjusting tube to the front seat back pad adjuster located in the seat back.

The pad adjuster seat control switch performs three functions:
- Turns on front seat back pad adjusting pump.
- Acts as a one-way check valve which maintains air pressure in the front seat back pad adjuster.
- The check valve opens to deflate the front seat back pad adjuster. (In this mode, the front seat back pad adjusting pump does not operate).