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Jordan80
09-30-2010, 12:57 PM
This may be a simple answer but I searched here and literally every other audi forum. on facelift b5's there's no a/c button so does it just automatically come on when you put the temp down to low? i tried recharging my system but that didn't change anything and I don't feel the compressor kick on but I'm not sure if I'm even turning the a/c on?
thanks

revolution337
09-30-2010, 01:46 PM
if you set it to low, the compressor should kick on. if its not, you have a problem my friend.

Jordan80
09-30-2010, 05:39 PM
yeah i dont feel it kick on at all. most likely the compressor?

Euromike
09-30-2010, 05:43 PM
If you get under your B5, you can see the compressor on the right side of the car. Turn your car on, Turn the temp down low, and see if the clutch inside the part that the belt spins on is rotating. If not, try and spin it by hand. If you cant, you need a new compressor.

Dallas09
09-30-2010, 08:28 PM
If the compressor isnt turning on its likely many other things before its the compressor. A refrigerant leak, a bad pressure switch, and the A/C relay are all other more common possibilities, all of which would prevent the A/C from coming on.

Jordan80
09-30-2010, 09:12 PM
If you get under your B5, you can see the compressor on the right side of the car. Turn your car on, Turn the temp down low, and see if the clutch inside the part that the belt spins on is rotating. If not, try and spin it by hand. If you cant, you need a new compressor.
I'll check that out.



If the compressor isnt turning on its likely many other things before its the compressor. A refrigerant leak, a bad pressure switch, and the A/C relay are all other more common possibilities, all of which would prevent the A/C from coming on.
What's the best way to figure out which one it is, process of elimination?

Dallas09
10-01-2010, 10:21 AM
Yeah theres many threads on this so you can search to find some, but basically step one is to check for codes, if you have one on HVAC for an open or shorted pressure switch, youll want to get a pressure gauge to check to see if there is pressure in the system (meaning you have refrigerant), if you do in fact have refrigerant the next step is to short together the connector for the pressure switch (if your A/C starts to work then you know its the pressure switch). If you dont have pressure in the system you have a leak and need to look for it (leaks can be found by checking for green dye, or wet circles on the condenser-- the black radiator in front of the coolant radiator). If you have pressure and you determined it wasnt the switch, next it would be time to check the relay underneath the driver knee bolster with the other relays. If it isnt that, you might try manually giving power to the compressor to see if it turns on.

Euromike
10-01-2010, 10:23 AM
If you dont feel the compressor turning on its probably not, which almost always mean its toast.

See if your accessory fan is kicking on

99blueb5
10-01-2010, 01:21 PM
for face-light the a/c is turned on by pressing the ECON button, if the red led is on next to it then a/c is off. is its not on then a/c will be switched to on, you cannot charge the system without the compressor running, if its so low that the comp0ressor wont turn on then you going to have to trigger it on long enough for the system to take the refrigerent, correct way is puling a vacuum in the system and recharging it with the correct machine