first try and unplug the f129 pressure switch- right rear of engine compartment (next to passenger side strut tower) and turn on a/c. if the compressor and fan still turn on i would suspect the fan control module has failed. it the comp and fan don't with switch unplugged- replace switch and have system serviced somewhere that can pull vacuum and add dye. i would suggest you replace the thermal expansion valve and seals before you have it charged since they seem to leak commonly and they're cheap. make sure to get some pag oil on the seals before you install them

 

if the fcm failed though, wouldn't both the compressor and driver side fan not turn? this may sound dumb, but i honestly can't see a fan in my engine bay aside from the large radiator fan, but i'm just not looking hard enough probably. i just find it weird that my compressor and everything is turning despite the system being empty, along with no new codes for a bad pressure switch.

 

fan control module is on the fan shroud near the driver side headlight.

that module receives inputs from various sensors and turns on compressor clutch and controls speed of fan(S) theres two of those in there. one big one, and a little one. little one turns on when AC is on

one of the inputs is the pressure sensor.

the sensor has 2 switches inside of it. 1 switch opens when the pressures too low and closes when the pressure is within specs. the other switch stays closed until pressure gets too high. then it opens.

when you unplug it, you open both switches and the module should respond by shutting off the fan. if it doesn't respond then you either have a shorted harness which shorted the wires together perfectly to close both switches. or you have a confused module which needs guidance.

dont worry too much about that fan module. i only mentioned it because they fail all the time. and when they fail, they eventually stop turning on the fans all together and your vr6 overheats which can be very costly.

a quick check of unplugging the switch should give you an idea of where to go next

 

interesting update. today i was checking out the engine bay and realized neither of my fans come on when i turn the ac on. isn't the smaller one supposed to turn on when you turn the AC on? it was around 50 degrees today, but shouldn't it still run? i drove it pretty hard to get it heated up, and even after stopping with the AC on, neither fan was turning. is this a bad fan control module, or bad fan itself? the fans do not turn on at all. i also was on the verge of overheating one time at a drive-thru about a month ago, maybe that's relevant.

 

very relevant actually. the big fan should turn on when the engine is hot. the smaller one should turn on when the ac is on (however in your case thats irrelevant because you have no refrigerant in your lines)

at this point i would say you have a couple issues that need to be addressed. its all stuff that you could do yourself if your handy with a wrench. if not, get ready to shell out some dough.

start with the fan issue. unplug the connector going to the fan and see if you have power coming out of the fcm to the fan. if you do- buy a complete fan shroud with fans. you will have to pull the front clip to install the fans. you said you were on the verge of overheating... vr6 motors dont like that. while you have the front clip pulled. install:

crack pipe and thermostat housing (most vw tuning sites sell kits with aluminum pipes)
water pump (with metal impeller)

if you're limited on funds or not very handy. take it to a reputable shop to have the issue diagnosed. like i said earlier- you do not want to overheat your motor

 

i'm going to test the fans in a couple of days and make sure it's not them and the module itself. the car only was close to overheating that one time. once i got on the highway, i was back down to 190 in about a minute. aside from that one day, i am consistently at 190 in any kind of traffic. i read somewhere that the cooling fan only comes on when you're slightly above 190. is there any way to test the fan aside from connecting it directly to the battery?

i still find it odd that my compressor is turning despite there being no refrigerant. that seems inconsistent with the fan not turning because of no refrigerant.

i'm certain the thermostat and housing is fine as i checked all of that when replacing the clutch.

 

okay, so disregard everything i've said. i just found it pointless to start a new thread. the problem was in the fans which i replaced today. my system did in fact have refrigerant in it. i repaired the fans and now my big fan does run when i go slightly over 190 to cool it down. however, sometime between a month ago and now, i lost all of my refrigerant, so my compressor no longer engages and the smaller fan does not turn due to no refrigerant. my question is how can i refill the ac when the compressor isn't turning on. do i need to jump it to the battery to refill it?