Last July when we first bought our 06 Legacy (sedan), we noticed the A/C was cool but not as cold as in my 02 Forester.  Then yesterday I had commented how freezing cold the A/C in the Legacy was.  Then this morning my wife said the A/C was not blowing cool air and instead it was just like hot/vent air blowing in.  Just went out and tried it, blew cooler air just fine.  

I checked for the flourescent green spatter....nothing anywhere in the engine bay.  But I couldn't find the A/C lines because it's a different setup than the hi/low lines in my Forester.

I checked to see if the A/C clutch was spinning....yup...like a top.  

I checked to see if the clutch would turn off and on in rapid succession....yup...no problem.

I kept the A/C running for 5min just to see if it'd die out....nope.

Is this ringing any bells for anyone?  Anything else to check?

Thanks

-Emt1581

Everything works.  

What I'm trying to figure out is what specific flaw in the system could cause a fluctuation in how cold the A/C gets?

Thanks

-Emt1581

I'm not sure what a blend door is...maybe a door that opens and closes depending on the desired/needed temp.  

Throughout the weekend the A/C worked perfectly.   No issues I could feel.  Might have just been a fluke thing.  

Thanks

-Emt1581

the blend door allows heated air into the air flow when you have a/c on and you want it a little warmer.

I don't know on a subaru, but on most others, GM, Ford and dodge, they are vacuum powered actuators that move the doors from open to close.

I have seen on some cars a vacuum leak cause those doors to move to the hot position when they owners wanted a/c. so they would complain about faliing a/c or lack of charge.

but the test is when the engine is cold is there still an issue.
if not, blend doors get looked at first.

if yours are truly cable, (doesn't sound likely), then it cannot be.
but if they are computer or vacuum controled, then I would see if something was going wrong with the actuators causing these temp heat/poor cooling conditions.

Is it auto a.c. Or manual a.c.