1995 1500 ac works intermittently

[southernfarm97]

Im new here seems like a very knowledgeable group and glad to be here I have a 1995 Chevy 1500 99k Miles The air flow out of the vents will stop working from time to time after driving for a while sometimes it takes 10 minutes sometimes a hour or so on the road blower Is still working when it goes out just get no air out any vent. i have replaced mode door actuator and fresh air/recirculation actuator and doesn’t seem to have helped any ideas would be appreciated thank you.

 

[east302]

Evaporator frozen up?

I had a 98 that did that years ago, the refrigerant was low. Turning it off for a while to let it melt usually helped.

 

[someotherguy]

Evaporator frozen up?

I had a 98 that did that years ago, the refrigerant was low. Turning it off for a while to let it melt usually helped.

Beat me to it. Sounds exactly like what is happening. Turning the A/C button off so the compressor disengages (also be sure the dial isn't in defrost mode as that will run the compressor) but leave the fan on, as the ice melts it should begin blowing again, and will still be cool air as it's crossing what's left of the ice. As it goes warm again you turn the A/C button back on and it should begin cooling normally - until it freezes again.

Richard

 

[pressureangle]

Agree, probably a frozen evaporator. You can verify this, to clarify the above, by turning the A/C to 'vent'- leaving the fan running but without cooling- and if it's frozen, you'll notice when it melts the air begin to flow but also that it's quite a bit cooler or even cold than you would expect precisely because it is flowing across that ice. After 5-10 minutes it will return to normal. It would be nice to know your system pressures, as low side pressure correlates loosely to evaporator temperature. Also, see that your low-side switch on your accumulator isn't bypassed as it disconnects the compressor when the pressure gets low enough to cause evaporator freezing. (usually)