Ac on 2001 vw golf tdi 1.9 blows hot air was working but stopped blowing cold air has freon and compressor clutch is good

low or no freon---- compression problem

Vacuum leak most likely, thus not operating air blend door.

Make sure your blend door is closing all the way and that the actuator actually works.

mine does the same

Are you sure the relay isn't getting weak? Try swapping with another.

Sounds like the compressor has gone out of your AC system. They are not too terrible to change, but can be time consuming depending on location. IF the freon is good, check the compressor and you should here it at idle speed w/ hood open clicking on and off as the clutch engages and disengages when the AC is operated. If there is no clicking on and off by the compressor, new compressor will be required. IF it gets cold when first adding freon, and then fades quickly, it is likely a leak in one of the high or low sides of the lines between the coil and the compressor.

Hope this helps!

Chip

I would check the following possibilities:
1. Is compressor clutch working? - You need to do this when the ac is blowing hot air only - locate compressor drive pulley on engine - rubber belt wraps around it. Start engine and set to max ac. When the ac is blowing hot air, look at the center of the compressor drive pulley using a good flash light - watch it for a while, it should be spinning with the pulley - this means the compressor is engaged. If not, the compressor is not engaged. If your ac is blowing hot air, then the compressor should be engaged and running (trying to cool). If it is not engaged, then your compressor clutch is probably going out. Could be low voltage to clutch, but more likely the clutch is worn out and only working some of the time. Note: if working normally, the compressor clutch will engage and disengage in cycles- but the air should always be cold. If clutch is bad, compressor would need to be replaced (sold as one unit). This is tricky to diagnose and could take some time - you need to do it when ac is blowing hot air but set to max cooling.

2. Low on refrigerant or refrigerant has moisture in it? If your ac blows cold initially after being off for a while, then heats up, and continues to regularly cycle back and forth between hot and cool air, then the system may be low on refrigerant or the refrigerant may have moisture in it that is freezing and restricting refrigerant flow. An a/c shop can check refrigerant level and even replace refrigerant if moisture is suspected.

Could be other issues, but I would start with these.

Good luck

on my 99 devillle concours cold air blows from left and back vents but hot air blows from right vents

AC will not work with temps are cold even when it is turned on. The air is colder cause the temp is colder. The AC cycles in hot weather because the AC charge is low and needs recharging. You will know this if you open the hood run the AC and you will hear the clicking sound of the AC compressor magnetic clutch. You can recharge it easily buy buying a compatible can of refrigerant. I suggest buying the kit with the gage so you don't overcharge the system which will cause freeze ups

you need to have it diagnosed by a professional. These are complicated systems even to a trained tech. You may be over or under charged, have a clogged expansion valve, have a leak or many other issues. This model has a rcv refrigerant control valve inside the compressor which regulates the pressure of the compressor. If you notice the compressor never shuts off like conventional auto a/c's do the only time the clutch works is when you turn it on or off. Can be complicated.