Help! A/C blows hot air.

[aw3375]

I have a 1990 with electronic climate control. The blower comes on, but only blows hot air. I tried the diagnostic feature on the control and every thing shows that it is switching from hot to cold when A/C is selected. The only one out of range is parameter 30 (stored full hot value). The range should be 0 to 50 and mine shows a value of 60. The compressor clutch cycles on and off and the lines coming off of it get very cold. Even the blower housing gets cold, but the air coming through the vents is very hot. Any ideas?

Thank you.

 

[rlg]

Check for a vacumn leak . I believe there is a tree located on the manifold that can cause a problem. If that isn't it the fun begins!!!

 

[aw3375]

Thanks for the info. I didn't find any vacumn leaks. I did find some information about the blend door causing problems. It turns out that door was stuck allowing full heat into the car. I pryed it open with a screwdriver and it works fine now. All climate control functions now work properly.

Thanks again for the help.

 

[LT4man]

What type and size screwdriver did you use? Was this a Kent-Moore tool? Was your tool accredited by GM?



Thanks for the update!