TRailBlazer A/C problem

I have a 2002 Trailblazer and I have had some problems with my A/C lately. First the outside temperature sensor was reading 50 F no matter what temp was outside and the A/C blowing hot air, I cleaned it and researched online and found a way to reset it by pressing MODE/FRONT-REAR DEFROST at the same time, it seemed to work. Now I have a worse problem, the A/C seems not to work. I put it on AUTO and nothing happens, when the car goes over 40 mph then I can feel a little cool coming off, at over 80 mph it gets a little better but I have it in MAX and only blows like the minimum, do you know what could be causing the problem?

Does the fan blow when you select HEAT?

Was there anyting before this such as disconnecting the battery?

When you say “you cleaned it off” do you mean the outside temp sensor?

Usually I have just replaced this sensor when a incorrect reading was present

Now about your AC, are you saying you have low air volume or that the air that is comming out is warm?

Has anyone checked your AC pressures?

The compressor your vechicle uses is very prone to leakage.