I have a 1997 altima 2.4L the a/c cools good when it works,i have replaced the amplifier since there was a modification on it, and by-passed the compressor thermo fuse and swapped the relays around and it still will blow warm air for quite a while before it kicks in again. It seems to do it more on a very bright,sunny hot day and when it idles for a while like at a drive through. it is a manual system. any suggestions? please help!!!! burning up in N.C. Thank You