Air Cond stops working

subaru
forester

#1

My air conditioning will stop working while the car is running. It will be putting out cold air for a while, then stop. If I turn the AC off and then back on again after a few seconds it seems to recover, but I’m worried that this could be a sign it will give out completely. I’m not totally sure, but it may happen when I’m stopped and idling.

Any thoughts/suggestions? Thanks.


#2

Its the ac clutch wearing out. The whole AC unit will have to be replaced this is a common issue.


#3

Why would someone need to replace “the whole A/C system” because of a worn-out clutch on the compressor?
:confused:

Additionally, I will add that, if the OP’s problem is that the air starts out cold and then becomes warm, that could indicate freeze-up of the evaporator core.

Can the OP please explain the exact nature of the problem?
Does the A/C system stop emitting air after a few minutes?
or
Does it still emit air, but the temperature of the air has turned from cool to warm?


#4

When I start driving and turn the a/c on, it puts out cold air. After a period of time - 5-10 minutes, perhaps - it stops putting out cold air. It seems to happen most often if I’m idling at a stop light, but it hasn’t been happening for long enough for me to actually tell. I do know that it’s also happened while not stopped, so maybe that’s not significant.

I can turn off the a/c while leaving the fan on for 5-10 seconds, then turn the a/c back on and the air will become cold again. I almost always have the fan set to recycle air in the car so the air will get colder than if I’m using fresh air.

Hope this helps.


#5

I agree with @VDCdriver analysis that the evaporator coil is freezing up. As the warm, humid air hIts the cold evaporator coil, the moisture is removed. If the evaporator coil is really cold and the air is really humid, the moisture removed from air may freeze on the coil. Keeping the cabin blower fan on high may help. You may want to have the refrigerant low and high side pressures checked.
I had a similar problem once, except the system, once the cooling stopped, didn’t start cooling for quite a while. It turned.out that the radiator fan clutch was slipping and not moving enough air through the AC condenser. However, most vehicles now have an electric fan instead of a mechanical fan.


#6

Besides evaporator coil is freezing up, I would take a closer look at the clutch. You said that happens most often at low idle, i.e. when stopped. You can do this in your driveway… I suggest you turn the a/c on and observe the clutch plate. It should be turning, your engine fan should also come on. If you have two fans both must come on. Keep an eye on the clutch plate when the air gets warm. If the clutch plate continues to turn it is probably not the actual compressor and I would focus on the other option…evaporator coil is freezing up

If the clutch plate stopped turning as the air gets warm, you have bad clutch. It can be replaced relatively cheap without fooling around with the refrigerant.


#7

So, there are a few good possibilities for the OP to follow-up on, but I hope that he/she ignores the very bad advice that the problem necessitates replacing “the whole A/C system”.
:confounded:


#8

Concur with majority advice above, the OP just needs to have the AC system performance assessed by a shop. It’s hard to say what the specific cause is just based on the symptom, but the way it all works, the refrigerant runs around in a big loop. It is compressed by the compressor which heats it up, that heat is removed by a gadget in the engine compartment (near the radiator), then the compressed refrigerant is routed to another gadget where it is allowed to expand, which cools it off, and then it goes to a part inside the car that produces the cold for the air cooling effect, after which it returns to the compressor. It’s all moderated by another gadget which decides if the air coming out of the AC is the correct temperature, and uses that info to control the compressor. The shop will hook up pressure gauges at various places in the loop, and from that they can tell what’s wrong.

The more important thing is to make sure the shop who’s doing all this is experienced in AC diagnosis and repair. B/c modern AC systems are very cranky about not being serviced correctly, especially being over-charged w/too much refrigerant. And a cranky AC system will not serve you or your wallet well. So make sure to use a well-recommended shop.


#9

My ac is not blowing at all. We changed the blower motor and the connector. Still no luck. Any suggestions?


#10

Does the blower work on “heat” ?

btw, it probably would have been better to start a new topic instead of piggy bag on this one since your symptoms are different and questions and answer could easily get confused. You probably have a different car as well.


#11

It is doing nothing. The heat or ac are not working.


#12

Start your own thread by clicking on the link (at the upper right of this site’s home page) marked “+ New Topic”.

Please don’t glom onto someone else’s thread for your dissimilar problems with a different make of car.