This is going to sound like a dumb question, but here goes. My A/C is not cooling. Compressor sounds fine and engages/disengages with the ECON button just fine. Turns out there was no refrigerant, so I filled it with a small leak stopper and o-ring conditioner bottle of refrigerant, then up to 50 psi with a larger bottle of refrigerant (R134a all of them).

But the thing is, it won't cool. I set both the temps all the way to the left and it still won't cool. Is this something to do with the ambient temp? By the time I got everything I needed to work on this it was late in the afternoon and 61F. Is it just being ornery and telling me I don't need cold air when that's what I (*&*@#$*& want?

 

As you’d know, the HVAC system has many controls in place. Its sounding like pinpoint test time on each of the modules/sensors?
Or is it as simple as a block in the small line? I have the question, ‘why’ was the sealed system empty?

 

Without knowing the full details of the system I suspect a safety valve designed to open if there is too much pressure did open and release the refrigerant. I have to check it this week to see if it is still leaking. Either way this is above my skill level. An older system in a larger engine compartment I can deal with, but if I have to tear things apart just to troubleshoot I will take it to my mechanic.

 

You mentioned that the issue might be the low ambient air temp. I recall that you're not supposed to run the a/c when it's cold outside, but I don't know why.

Can you park it in a heated garage and try again?

 

One of the ways the A/C helps with moisture on the inside of the windshield is with cold air. Also, if ambient temperature were an issue, the temperature sensors should turn off the compressor when it's cold outside. ??

 

Good point. The Defrost mode is to clear up fogged windshields and I believe that uses the A/C. But I don't know if it's any different than regular A/C for cooling the passenger compartment.

 

....and the service manual, as usual, doesn't say squat about that.

 

Time to go find my mongoose cable and play god.

 

I leave my AC enabled almost all of the time, then it's up to the HVAC to use it or not.

The AC systems seem to be more reliable with regular use, I do this with all of my cars and have only had one failure ever (freon leak at 180K on a 1988 acura).

Also keeping the humidity under control (the "conditioning" part of AC) helps prevent nasty fungus in the ducts and other parts of the cabin.

The fuel/HP cost of AC in a modern car is almost negligible, it only gets significant if the AC is working *really* hard in which case you probably need it on anyway. Only time I turn it off is going up a steep mountain in hot/high conditions, and that's to save the airflow through the grill for the coolant and tranny.

The AC in classic cars actually used a lot of fuel and HP, but it's waaaay more efficient today.

 

I concur @merlinj79 . Like you, I just leave it on for the very same reason... it keeps the interior dry.
Good luck @flybd5 . I don't know enough about the LR HVAC to be of any more help. The HVAC in the Jag has 4 control modules and 3 sensors.