1991 Bonne A/C problem

I have a 1991 Bonne LE with 150,000 miles. Have had GREAT luck with this car but realize it is getting high miles. I recently drove it about 250 mile trip and the A/C worked perfectly staying nice and cold. The next time I drove it, when I turned the A/C on, it got cold after about 5-10 seconds and then it was like you turned only the blower on with no A/C. It does the same thing every time I turn the A/C on, gets cold fast, then just neutral temp with no cold air. I checked the compressor switch and it is working fine, and the compressor is engaging and staying engaged, but not outputting cold air except for the first 10 seconds or so. I do believe the temperature door inside the dash is opening properly. Any suggestions about what I might check myself before taking the car in for A/C service? I am capable of replacing the compressor & seals myself but would have to have someone discharge the system and then recharge it afterwards.

The car is a rebuilder that I bought about 10 years ago. The fellow (very trustworthy) who rebuilt it replaced all the A/C o-ring seals when I bought it and made sure the system was fully charged. It has worked perfectly this whole time. He also gave me the a/c compressor and other parts from the parts car that was used to rebuild this one. Any suggestions would be greatly appreciated! Thanks!

maybe a bad ground or possibly a bad conection check both

So, the compressor runs.....vehicle is cold for 10 minutes......then the cooling is lost, but the compressor is still running?

When the vehicle is cold in the first 10 minutes, feel the low side line...naturally, it should feel cold.......now when the interior air starts to get warm after 10 minutes, feel that lowside line again.....if it is still cold, check the temp door......

If that line doesn't feel cold, I'd put a set of gages on the hi and lo sides.....see what the pressure is when the vehicle is cold, and then when it goes warm, see if the pressure is dropping.....

There is the possibility that the evaporator is freezing up, and your cooling would diminish, but also so would the air flow....