I have a 1989 Cherolet pickup with factory air. When I turn on heater or defrost, all the air comes out air conditioning vents. How do I fix this?
have the same problem?
Saturday, December 4th, 2010 AT 12:09 AM
The airflow vents are actuated by vacuum. Check for vacuum leaks under the dash. If you are lucky, you may hear a hissing sound with the engine running.
Saturday, December 4th, 2010 AT 7:08 AM
89 model has electric blend door motors. Mode door motor is located on left end of heater assembly, look under dash on driver side between colum and hump.3 inch square box 1/2 inch thick easy to access.