Ford Power Stroke Nation banner

Air conditioner not blowing cold air

43K views 12 replies 6 participants last post by  Brimmstone 
#1 ·
AC is not blowing cold air. should be charged, my other guess is that its the compressor, any ideas on how to tell if its gone bad?
 
#2 ·
Is the clutch cycling at all?

Is there excessive in/out play on the compressor shaft?
 
#3 ·
since there is already a thread started with this i wont start a new one just bump this one.
yesterday when driving home my ac stoped blowing cold air when i got home i looked and the compressor is cycling the line where it goes into the firewall is getting cold when the compressor is on but it doesnt stay on but just a second or 2 and turns back off. i took my ac gauges and connected them to the high and low side and the pressure on the low side would start off around 40 to 50 psi then drop to just under 20 and the compressor would shut back off then come back on when it got back around 40 to 50. the high side was anywhere from 240 to 320 psi. i had a can of 136a refrigerant i thought maybe it just needed a little freon so i hooked it up and put some in it just a little and it started cooling again but not cold i only got the low side up to around 30 psi i cant remember excactly what the presures are supposed to be. so my question is is there anything i should check that would make it not want to blow cold air and what are the line pressures supposed to be its been awhile since ive done a ac system and cant remember.
 
#11 ·
these are the correct readings for this if anyone else has problems
A/C System Pressure Readings
Ambient Temperature Low Side Pressure High Side Pressure Center Vent Temperature
60 °F 28-38 psi 130-190 psi 44-46 °F
70 °F 30-40 psi 190-220 psi 44-48 °F
80 °F 30-40 psi 190-220 psi 43-48 °F
90 °F 35-40 psi 190-225 psi 44-50 °F
100 °F 40-50 psi 200-250 psi 52-60 °F
110 °F 50-60 psi 250-300 psi 68-74 °F
120 °F 55-65 psi 320-350 psi 70-75 °F


Clark's Garage © 1998
Normal readings on high and low side with AC OFF (static pressure) - Depends on outside temperature, but normally is between 80-105 PSI
Normal low side reading with AC on high speed and MAX & engine at 800-1000 RPM’s - Ranges from 25-35 PSI - Note that on many Chrysler products a normal reading on the low side may be 15-25 PSI
Normal high side reading ranges from 200-350 PSI
 
#13 ·
If you have a smart phone download the Bitzer app. It is a full Pressure Temperature chart. I usually go by high side pressures. Take your ambient temp and add 40 to it. That is the temp to look at on the app. Has option for *F and *C plus PSI and BAR. I use it all the time when I work on buses. Be glad you have a small system. The buses I work on used anywhere from 20 to 28 pounds of refrigerant.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top