86-89 C68 HVAC Service

Common Problems

  • The climate controller buttons, bulbs, power supply, capacitors, internal connectors and the display commonly fail.
  • Switches don't work
  • The faceplate detaches from the circuit board
  • The display and LEDs flash like crazy and display jibberish info.


The HVAC programmer module houses vacuum control solenoids and the blend door motor controller.
- Heat and vibration can cause the solder joints to break down - Power Supply capacitors frequently fail - The blend door circuitry frequently fails, causing the unit to blow hot when cold is selected, or cold air to blow when hot air is selected - Solenoids can stick on or off, causing air to be diverted to the wrong location


  • The Blend Door Motor selects heat or cool air. Moisture and dust from the system can cause the motor to seize or the motor position control to fail.


  • The Blower Control Module transistor fails frequently. We can test this component, but it is sealed and not repairable.


It can sometimes be difficult to know which component(s) have failed, so we're here to help. If you don't know what the problem is with your AC, you can always contact us and ask which components to ship. Feel free to ship all four components. We'll test everything together at no charge!


All Services Include

  • Free inspection of the climate control internals

  • Complete cleaning inside the controller and other modules

  • Bench test of all C68 HVAC components and all functions of the controller, programmer, blower control module and blend door motor

  • This is not an exchange service. Your components will be returned to you!

  • 1 year warranty on parts and labor



  • Repair 86-89 Programmer Component: $125.00

  • Repair 86-89 HVAC Controller:  $275.00


Here are links to the exact repair processes we offer. 

86-89 Programmer Repair

86-89 Controller Repair

    These repairs are the most common needed for the 86-89 Electronic Climate Control, and do not include replacement of missing components, or the replacement of display or logic board. When your components arrive, we will diagnose each at no charge, then contact you with photos of the problem and an exact repair total, and wait for your approval before making any repairs.



    Before You Ship

    Before you send the climate control components, check the following:

    • Check the GAGES and CTSY/CLK fuses.
    • If you're having problems with the blower motor not turning, check the A/C Underhood Fuse
    • Turn on the ignition, and watch the "Ext Temp" light. If it flashes, count the number of flashes and report that info to us. Also look at the display and tell us what number is displayed.
    • The programmer module is located in the drivers side footwell, just above the gas pedal. Follow the colored vacuum lines to it. There is a metal keeper which holds on the block of vacuum lines. Use needle nose pliers  to remove it, or just cut it with diagonal cutters then remove all vac lines as an assembly. We ship the programmer back with a lock nut that will let you reattach the vacuum lines.