High operating effort on A/C control mode select levers may occur on some 1984 Camaros. Highest effort is experienced when moving the lever from heater to defrost.
This condition can be due to the vacuum control select valve binding. Affected parts can be identified by the black color of the stator part of the valve.
This condition can be repaired by replacing the vacuum select valve assembly with one that has a white stator. Part number is the same for both designs (16032395).
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.