Mitsubishi Galant Air Conditioner Problem


I have a 2002 Mitsubishi Galant. I am having some trouble with my airconditioner. It works sometimes. Sometimes it blows cold air and then the next minute it will blow warm air. It has been to the dealer 3 times and to the local mechanic once. The problem is still the same. The first time I took it to the dealer they charged the system and put some dye in it. I took it back and I was told I needed seals. When they put the seals in they broke the condenser and they replaced it. No change in the problem. During a trip back from the beach the airconditioner worked for about 20 minutes and then didn’t work for 10 hours and then started working again for the last 3 hours. Took it back to the dealer and now I need a new compressor to the tune of about $1,000 with labor. I didn’t feel confident that they knew what they were doing and then took it to a local mechanic who discovered that the compressor was not fully pluged in. The same problem persists. Any ideas?