A/C Problem

[JCRowan]

Hey Fellow NSX'ers! Here is my A/C saga, hopefully someone can give me guidance or suggestions on this.

I started to notice that my A/C was blowing hot, not warm, but hot air. So I turned of the climate system. I still hd about an hour to drive, but it was a nice evening. By the time I was arriving my destination I thought my feet were going to melt. Very hot air not blowing, but being directed into the cabin in the pedal area. So I took it in to my mechanic at the Acura dealer. First they had to convert my A/C to the new freon (ru134?), my car is a 1991 by the way. So they converted it and filled it up with freon. They left it overnight and there was no leakage, so we assumed the problem was fixed. But about a month later, boom, back to the same problem. Hot A/C, and when off and I drive the car for anything more than 1 hour, my feet start to melt. I just thought this was strange that there should be hot air still coming into the cabin even though the climate control unit is off. So whatdaya think??? Now they did put the dye in with the freon so that if it did leak out they could trace it. but I thought I would hear what you all thought before taking it back in. Thanks!

 

[NSXTech]

If you sit in the car with the engine running and the fan on medium, can you switch all the modes (from dash to floor to bi-level to defroster)? Can you get cold air in any of these modes? Did the a/c work for the month since the last visit? If so, did it function totally normal? If you can answer these Q's, I can probabally help.
As a rule, hot air will always overcome a/c if both are on (a/c compressor on with heater on high) so I am suspicious of a few things.

MB

 

[JCRowan]

Thanks for your help, I shall try to answer all your questions. Keep in mind that I am not mechanically inclined. I would even say I am in the challenged category and appreciate your help.

I am able to swith to all the modes with the engine running. It was in the vening and even though it didn't blow 60 degree cold it was at least cool, but that could be because it was a cool evening out and I was driving while doing this. The A/C did work and belew cold for about a month after the service. The hot air occurs when it is hot/warm outside and I have been driing for more than an hour. It has been melt the feet hot when the climate unit was completely off except for the outside air flow on. It has also been very hot with the A/C on as well.