Thread: Pressure Switch Location?????

Can anyone help my locate the Air-con pressure switch on my S3 8L (2000).

I might be being stupid but cant locate it.
I need to test the switch before i go and buy a new one.

thanks

You may have more luck in the 8L forum mate.

its behind the heat sheild at the back of the turbo

On the A4's the pressure switch is located on the air-con radiator near the pass side headlight, its just a unscrew and change job..

Does the system need the gas removing first? My A4 has a blown fuse 6 (air con pressure switch) and blows a new fuse as soon as the ignition is swiched on. I'm thinking that if the wiring is ok (will test for a dead short at the plug when I find the damn switch) then the pressure switch must have died and gone dead short.

Yes mate if you want to change the pressure switch the whole system needs to be recovered

How the hell can you get to the sensor? Please tell me you don't have to remove the front bumper!!

You may have more luck asking in the A4 forum mate.

Originally Posted by Wobbler

Does the system need the gas removing first? My A4 has a blown fuse 6 (air con pressure switch) and blows a new fuse as soon as the ignition is swiched on. I'm thinking that if the wiring is ok (will test for a dead short at the plug when I find the damn switch) then the pressure switch must have died and gone dead short.

No it doesn't (B6 A4) it just unscrews and unplugs..

Originally Posted by mike-turbo

its behind the heat sheild at the back of the turbo

Yeah this is where it is I believe, as thats what I had to change on my late 99 S3 once, I lost cold air, so changed this which was £50 & it worked again, its slightly more to the right IIRC from the turbo, but is hidden behind the heat shielding in that area attached to the silver pipes & as already said, they emptied system then regassed to do the job.

Originally Posted by technics100

No it doesn't (B6 A4) it just unscrews and unplugs..

Ok if you do it that way you'll vent all the refrigerant!

I would have to agree, given the name of the actual switch it would suggest its not a good idea to undo it without removing the pressure it reads, given its refridgerant that wouldnt be wise huh Staz.

...and illegal!

Plus it would allow air into the system if it was done that way so it'd have to be deep vacuumed before recharging.

I have read that the switch screws into a valve assembly similar to a tyre valve, although this would mean some gas would escape as the valve was removed/fitted.

Think I'll get the garage to do it for me.

Advisable mate, given the system involved & yes, iirc, it just screws onto the pipe as such.

Yeah and as the refrigerant escapes it super cools and will give you frostbite.

Sooo. gloves would be advisable then?.......just kidding, given that the bumper has to come off and that I have no inclination to undertake a job I'm unsure of, I'm gonna book it into the dealers.

Why take it to a dealer mate, take it to any garage that has an ac gasser, they can remove the bumper & re-gas for a hell of alot cheaper than audi for sure.

Changing the G65 pressure switch does not vent the system. I have changed the sensor, it just unscrews and the new one screws in.

Originally Posted by technics100

Changing the G65 pressure switch does not vent the system. I have changed the sensor, it just unscrews and the new one screws in.

How does it keep the refrigerant in then?