A/C blowing cold intermittently

[hockeylvr93]

I have a 2005 Legacy(not GT) with 263K miles on it. Recently, as I am driving the cool air turns warm, at times, I can hit the button off/on and that will make it work again; other times, if I turn off the fan completely and back on that might work. Over the weekend, if I opened the window while it was blowing warm it, it would start to blow cold air (coincidence?)

 

Any ideas for solutions?? I just had a new moter put in 15K ago (late April) the A/C was evacuated and recharged at that time. Checked all connections under the hood, when it does blow it blows ICE COLD, so it's not low on freon.

 

Is their an ambient temp sensor? or their any control modules?

 

thanks!

[mrfixiter]

What happens if you're just stopped with the motor running? Is it still intermittent? The reason I ask is because it will be much easier to troubleshoot if the problem happens when the car is parked than when you're driving down the street. Youtube has some great videos on a/c systems. Though they don't apply specifically to your problem, you may pick up some helpful tips.

 

Good luck.

[nipper]

I bet your low on refriferant. At that mileage you probably have a leaky O ring.

[hockeylvr93]

What happens if you're just stopped with the motor running? Is it still intermittent? The reason I ask is because it will be much easier to troubleshoot if the problem happens when the car is parked than when you're driving down the street. Youtube has some great videos on a/c systems. Though they don't apply specifically to your problem, you may pick up some helpful tips.

 

Good luck.

 

Thanks for the links, I will certainly check those out.

 

It happens parked or driving

[1 Lucky Texan]

marginally low refrigerant as said, also, check the cabin airfilter. Ice can build up if airflow is blocked.

[hockeylvr93]

as i originally wrote in april i had my a/c evacuated and recharged when i got my new motor....so i really don't think it's a o ring or low refrigerant

 

thanks

[Rooster2]

as i originally wrote in april i had my a/c evacuated and recharged when i got my new motor....so i really don't think it's a o ring or low refrigerant

 

thanks

 

There is no guarantee that you still don't have a bad O ring or low on refrigerant even if you worked on the system back in April. I would still add a can of R-134a, and see if that fixes it. If so, then it must be leaking refrigerant somewhere.

[1 Lucky Texan]

borrowed gauges from work and just this weekend took a look at our OBW H6 - wife complained thursday night about no/intermittent cooling.

 

I inspected around the 2 lines on the compressor, H line seemed fine, L line may have had some slight oil stain on the back side - no buildup of grime or wet-looking.drippy area at all so, I decided to leave them for now (I did buy some a/c o-rings just in case)

 

fans were working, compressor seemed to work. St first, blowing cold - then would kinda warm up, maybe icing?

 

anyway, gauges showed low on refrigerant. I put in 'maybe' 7 oz (plus or minus - hard to tell with the hose attached) and it's doing much better. I figure most of the summer it wasn't ever cycling and that may explain my poorer gas mileage this summer.

 

I used the refrig. that has a dye but no sealant. If the a/c perf. drops off in the next few weeks, maybe I'll know where the problem is.

[yohy]

To quote post #6 on this thread (http://www.subaruforester.org/vbulletin/f88/ac-fine-till-its-hot-57077/):

 

A common problem on all compressors w/ on-demand clutch is failure of compressor to engage due to wear of clutch plate, causing clutch plate gap to become too large. This gap results in coil magnetic field being too weak to pull the plate in against the spring. You can verify if this is the problem by rapping the clutch plate sharply w/ a stick when AC should be running. If the clutch plate closes and AC works, you've verifed that clutch gap is too large.

 

Fix is easy also. Remove clutch plate (usually a 10mm head size bolt) and remove a single thin shim from beneath the clutch plate. Measure clutch gap w/ a feeler gauge to verify it is w/i spec, usually 15-25 mils.

 

 

Also check out this thread as it will contain some valuable how-to steps:

http://www.subaruforester.org/vbulletin/f88/c-compressor-clutch-95352/

 

Hope this helps.