Ac dryer is cool when compressor kicks on hot wen it kicks off what is going on? on 2000 Mazda 626

I changed office tube vaccumed system down and charged the system it was blowing perfect then shout out freon wasn't over filled so I changed compressor and the guy bought a used dryer from pull a part I installed it and a new office tube vaccumed down the system and charged it back up I get cool air not as cold as it was at first wen the compressor kicks on the fan comes on and the dryer gets kool when the compressor kicks off ac fan goes off dryer gets hot warm air can anybody help me out

Asked by for the 2000 Mazda 626