The a/c in my Jeep works very well… until it doesn’t. It’s icy cold, and after maybe 20 minutes it’s just blowing outside-temperature air. I thought the refrigerant might need topping off. When I put on the a/c filler attachment, it read almost halfway into the blue (proper pressure) zone. May as well top it off. I screwed the can of refrigerant into the other end of the hose and… nothing happened. I don’t see any sort of ‘on’ button on the filler hose.
Anyway, given that the refrigerant pressure is nominal, why would the a/c stop working after 20 minutes?
I had this happen on a car I had. What was happening was the evaporator was freezing up, restricting air flow which eventually stopped it, the only air that got through was somehow taking another route. My ‘fix’ was simply to turn off the a/c for a bit when it stopped cooling (but leave the fan running), the cool air gradually returned as the ice melted and opened up air passages through the evaporator. When it started getting warm again due to the ice melted mostly away I would turn the a/c on again. I would rinse and repeat to my destination.
That’s what I thought, and what I do. Last week I lost a/c. I parked in my driveway for a while. When I went out again, the a/c was back. I expected to see a puddle under the front, but didn’t see any. Shouldn’t melted ice be evident?
I would think so, but really I never checked. It worked well enough for me. I know my current ride with properly functioning a/c can leave quite a puddle.
Just to make sure, you did have the engine and A/C running when you tried to top it up?
Affirmative.
I assumed the gas would just start flowing when I screwed the hose to the can.