AC trouble

[tommy.powell@fluor.com]

I have a 1989 Z71 1500.I have pulled a vacuum on the system and recharged with a low side pressure of 50 lbs. and it still blows hot air.Does anyone have any suggestions?

 

[98trck]

does the compressor clutch energize and engage
did you full it up with R12 or R134

 

[tommy.powell@fluor.com]

It does energize for about a second or two.Charged with R134a.

 

[98trck]

it sounds as if the pressure switch has gone bad
it has two wires going to it it is on the side cylinder tank shaped left side of firewall
unplug it and jump the two wires in the plug that will energize the compressor clutch
usually you do this while charging the system if the compressor won't run constantly because there is not enough pressure in the system
so I wonder if you did get a full charge in the system
and your truck is a 1989 it was probably an r12 system
so I wonder if an r134 conversion kit has been installed

 

[tommy.powell@fluor.com]

It does have the 134a kit.I jumped the pressure switch to charge,still blows hot.When I go home,I'm thinking the drier or orifice valve.

 

[98trck]

you sad the clutch only energizes a second or two
it must stay engaged