Blower Switch

Remove control protection cover (Riviera), instrument panel cover and right defroster hose (all other models), then proceed as follows:

Fig 1: PILOTED VACUUM ACTUATOR (PVA) ASSEMBLY

Courtesy of GENERAL MOTORS COMPANY

1. Connect Brown vacuum hose (removed from TVR connection) to regulated vacuum port of Vacuum Regulator J-22860 and connect regulator source hose to Black source hose of TVR
   CAUTION: (Regulator valve must be  open when connecting regulator to PVA).

   Connect a vacuum gauge to third port of J-22860 Regulator. Operated engine vacuum to PVA and Vacuum Regulator, position selector wheel in HIGH blower range.

2. Slowly reduce vacuum to pilot side of PVA to 0" Hg. and check for high blower speed (12.5 volts) in maximum heater.
3. Increase regulated vacuum to pilot side of PVA to 8" Hg. and check for high blower speed (13.5 volts - high blower relay energized) in maximum A/C.
4. If blower does not operate in this manner (steps 2 & 3), loosen blower switch mounting screws and adjust blower position by sliding switch endwise (mounting screw holes are slotted) as necessary. Recheck operation.
   CAUTION: Make certain that blower switch does not bottom out in either position (0" - maximum heat or 8" maximum A/C) which would prevent proper temperature door sealing.