Air conditioner stops blowing while accelerating... What gives???

[bori2150]

I have no idea what causes my 2002 4.0l air conditioner to stop blowing cold air while accelerating or under load. It works fine other than that and has sufficient freon 134a .... Any ideas?

 

[Turdle]

The Wide open throttle circuit disables the AC compressor during heavy load acceleration. This is normal.

I think all modern vehicles have this circuit.

 

[Joe Dirt]

Jon is right- define "accelerating"

 

[bori2150]

I should say accelerating under load, like going up a hill. It happens at part throttle also. I read somewhere that it could be a vacuum problem but I have no idea where to start looking. I work on my x all the time but this one has me stumped.

 

[Joe Dirt]

Yep- something is amiss if it does it even under part throttle. The kickout should only occur at the top of the TPS range.

 

[skeeter123]

Does the air keep blowing, but just gets warm, or does it start to blow out the defrost vents vice the console vents?
If it changes vents, it could be a vacuum leak, where vacuum is strong enough to move the vent door actuator, until you mash on the gas, vacuum goes down, and then the actuator spring overcomes the vacuum. The actuator I'm thinking of is shown in this thread:
http://www.explorerforum.com/forums/showthread.php?t=249624&highlight=vacuum+actuator
You could check to see if the red vacuum line is on all the way, not leaking for some reason.... you may be able to see it without taking off the glove box; try putting your head down where the passenger's feet go, and look toward where the back of the radio would be. Those red and yellow lines are vacuum control lines, maybe one of them is off/leaking.
Hope this helps.

 

[xsorcist]

I had this same problem on my Manual 2003 Explorer Sport XLS It was a vacuum problem. There was a part that was supposed to prevent the vacuum from returning but the diaphragm on it was broken so it was messing up the vacuum and causing the AC to stop blowing air when the car accelerated under a bit of stress.

 

[Daniel Beltran]

On my Ranger the problem was a burned vaccum hose, the gray one that is conected to the heater control valve. You must check the hoses to see if one is disconected or broken.

 

[Daniel Beltran]

On my Ranger the problem was a burned vaccum hose, the gray one that is conected to the heater control valve. You must check the hoses to see if one is disconected or broken.

 

[TechGuru]

Bad "Check valve" somewhere.

 

[DirtJack]

My 1997 Ford Explorer does a similar thing. Just under normal driving, city streets, stop and go traffic it works for maybe 15 minutes then cuts off. Blowing hot air from the dash vents not the defrost. Is this a vacuum hose issue? AC works fine if outside temps are in the 60s. Once you get over 75 outside it stops blowing cold and blows hot air. Compressor does not come on.

 

[TechGuru]

My 1997 Ford Explorer does a similar thing. Just under normal driving, city streets, stop and go traffic it works for maybe 15 minutes then cuts off. Blowing hot air from the dash vents not the defrost. Is this a vacuum hose issue? AC works fine if outside temps are in the 60s. Once you get over 75 outside it stops blowing cold and blows hot air. Compressor does not come on.

Sounds like high pressure cut out.

How's your cooling fan functioning?

 

[DirtJack]

Sounds like high pressure cut out.

How's your cooling fan functioning?

It's running, seems to be spinning when the condensor turns on while the vehicle is in my driveway. I have since found out that the original Thermostat housing has been leaking coolant from the dreaded seam. Going to replace that then look into the AC cutting out. Seems connected to the WOT sensor. If I go over 2500 rpm it cuts out and does not come back. If I can get on the freeway, get up to speed and just drive at 2500 at around 70 it will sometimes stay on for over an hour.