GT temperature control switch is jammed stuck etc,bouncy

Sounds like the "blend door" is either stuck or the cable attached to the control needs to be fixed (either by removing it and greasing it up, or by replacing it) or that the control itself is stuck. See the instructions in a Haynes or Ckiltons manual for removing the a/c panel. Extract the cable, see if the blend door is jammed, and if not, inspect the cable for kinks or corrosion. If it is not the cable or the blend door, then inspect the control and the gears that extend the cable in the control. They may may need to be lubricated, or the contol needs to be professionally fixed or replaced.