I have a 1990 Chevy Lumina 3.1 I have no heat the blower blows but does not blow hot air my coolant is fine and the engine temp is at normal operating temp. I have flushed the core and run Prestone Radiator Flush as directed. I can feel a change in air flow when I move temp control to Heat and select Heat. Also, if I switch to defrost, the compressor comes on but air does not switch from front vents.
I disconnected the hoses at the firewall going into the console area and using a shop vac to blow air, I connected hoses so that I go push water back through and out into a gallon jug. THe fluid was green with minor amount of trash. After that is when I put Prestone Flush and ran the car for a couple days> Today I drained that and filled with Peak 50/50. Having no temp problems at all.
Checked all fuses and popped off console. Then I realized that the heat/air switches are like an enclosed mother board and stopped.
February, 23, 2013 AT 8:43 PM
You will need to check the blend door motor to see if it is moving the door to the heat position.
February, 23, 2013 AT 9:00 PM
Thanks Roy.I will go get a Haynes Manual. I did not know what part to look for.