D3Audi

So we're finally getting some warm weather in northern NY and I went to turn on my AC in my 08 Q7, well, it turned on for a few seconds, and then turned back off and I can't turn it on until I restart the car. So Econ mode is stuck on. I ran a scan with my Carista app and it said that theres a fault with the "High Pressure Sensor (G65)"... does anyone know where this is located? I'm thinking this is definitely the cause of my AC not working. Or a bad blower motor. What does everyone think?

smith2010Q7

1st you need to removed the Refrigerant before removing the High pressure switch. (or it will blow up in your face under high pressure)


Audi Q7 G65.pdf

Greystoke

Usually located just after the A/C compressor on the metal tubing which goes back to the cowl. The rubber covered hose should be the low pressure line. As stated do not remove the High Pressure Switch without first evacuating the refrigerant.

If your blower is turning on with just the fan selected then there should be no issue with it.

Grey

69RS

Had the same issue with mine. Blower would come on then go off. In my case the blower was bad. If your blower isn't working on other settings either, replace the blower. Easy to change out, it's under the glove box.

J. Patterson

Mine was a blower motor too. Compressor would shut down and even rear air would not work. Engine off then back on would sometimes make everything work but we had a hot uncomfortable ride home from Charleston SC before I figured that all out.

D3Audi

Thanks for this! How would I go about removing the refrigerant? I'm not real familiar with the air conditioning system. I'm having a hard time even finding the high pressure switch under the hood lol

D3Audi

There was one day my blower stopped working entirely and made a knocking noise. But it seems to be working fine right now... only time will tell

smith2010Q7

Have to say, need to go to a shop that has a AC evac machine.
What I do is to have the shop Evac the AC then i go home replace the part and return back to the same shop for a refill. Some shops will charge a flat feed, one I go to charges me 100.00 for a Evac and service without charging me by the (Once).

If the shop going to charge you by the Once you need to know how much they have taken out so they can not double charge you. Example, you taken out 500g so you will get charge for 250g.

A/C Refrigerant

Capacity

Single evaporator 700 ±50g (24.7 ±1.8 oz)
Dual evaporators 1050 ±50g (37.0 ±1.8 oz
TDI 1050 ±50g (37.0 ±1.8 oz)

D3Audi

Thank you for this again. I have been researching this over the past week... some people have said that you don't need to evacuate the ac, others say you should, and others say you need to. I'm a little stumped. I looked up a couple videos on YouTube on the replacement on other Audi/vw models and it looks like they just unscrew the sensor and put a new one there. What do you think? You know a lot more about this than me. Lol. Is this something any mechanic could do?

J. Patterson

There is a Schrader valve under the pressure sensor that seals while it is swapped. The question I ask is, Do you really need a sensor or do you have a radiator cooling fan issue that is actually resulting in a high head pressure situation? It is advisable to have a tech check the operating pressures before swapping parts. Good Luck!