need A/C help for a jeep...I know,I know

[twoslo4five0]

Ive been trying to get my nieces A/C working in her 94 grand charokee today..i bought a can of 134a w/ a guage...alright on the low pressure line it gets freezing cold like its working..the guage with the ac on and running reads normal but with it off it goes to danger...what could this be...id really like to fiqure this out!!thanks guys

 

[Jason4x4]

when you shut the ac off, the pressures are going to equalize, so high and low sides are both going to read ~100 psi. So the low side going to danger with it off is normal.

 

[twoslo4five0]

so any ideas on it not working???

 

[Jason4x4]

You said the line is cold right? So I imagine that the air coming out of the vents isn't. Could be a blend door problem under the dash.

 

[5280k5]

What does the low side pressure actually read on the gauge?
What's the air temp coming out of the vents?
With r134 it's pretty important to see the high side pressure too, system's are very picky about the system charge and can't really see what's going on w/o both sides of system being monitored.
Can you tell if the temp door is actually changing from hot to cold? Usually there will be a slight increase in air flow when going from hot to cold as the temp door changes poisition.