We just bought a new to us sequoia that a/c wasnt working when we bought it, we got a great deal on it and we took it to a local shop, they found a fitting on the compressor that was loose and tightened it and put a vaccum and recharged the air, Blew ice cold for about 5 days, now it will start up only blowing cool, not cold and has to be run on high, but if you turn the rear air on in a matter of minutes it starts blowing ice cold again? Then after 15minutes or so it will fade away and you have to turn off the rear air and wait and turn it back on? Im so confused? Im thinking there is a small leak somewhere and when turning on the rear air it kind of primes the system a little to blow cold for awhile ? Any ideas ? Thanks in advance!