Hi, I've not had ice cold air con working in a 2005 BTC. The gas is full. What could the fault potentially be and cost / remedy for this? I've heard that sometimes the compressor may need a restart diagnostically?
Thanks

 

Well too high pressure and the comp cuts out .Too low obviously.
How do you know the pressure or weight of gas is within spec ?

If you remove the cover on the scuttle the hvac control valve is to the left of the central air intake .
Two electro / solenoids , one blends cold water from the compressor the other hot from the back of the engine .
You can put your hands on the two cold in or see condensation if the compressor is actually working and cooling the water .
If the valves fail they fail open so too much hot water comes into the blender .This knackers the cooling effect .
Because it’s climate control the blender is constantly adjusting the mix of hot and cold water using the two solenoids .

So check the multi pin connections sockets going into the control valve .

Or clamp off the hot feed in , if there’s condensation on the cold in pipes .If it turns ice cold then the hot blender is knackered and defaulted open .Its default is open for safety etc on cold winter days to clear the screen .

A new blender is a denso ( Japanese ) part £1300 from Bentley or approx £3/400 from eBay used .

Any corrosion of any relevant multi pin sockets in that scuttle likely to shorten the life of the blender solenoids so it’s important to keep the drain patent , clean leaves out etc and imho park the car inside out of the weather .

 

The blender , you can see the black circular tops of the two solenoids, and the pipage going in Ignore the big grey one that’s my improvised hover to keep the scuttle drain patent

Red is hot water in Blue cold - should feel cold / condensation etc Green the two solenoids The copper is my improvised drain hoover .
There’s multi pin plugs out of shot at the back .

 

Lol funny Ive seen a pipe attached to the vac I had to make up one the other day left the car under the tree over night by mistake and it was windy over night, next morning it was like the tree was all over the car and these little bits were everywhere & I mean everywhere got into the air vents had attach a peace of hose pipe so I could bend it under the front drain ...

 

Hi Shang I've had problems with mine so took it to a friend's garage and removed the gas then refilled it after a pressure check we started it up and nothing but warm air.i then read up the system needs to be diagnosed and then reset so I got my trusty £65 diagnosis machine out and low and behold it reset the system and now I've got working Aircon I'm hoping this might be the same for you fingers crossed

 

Thank you for the photos. This aspect of the Bentley hvac system I wasn't clear on. For future reference this is good to know.👍👍

 

@Yoghurtshotgun Thank you for the info - I'll follow up

 

Thank you for the detailed information - really appreciate it. I will have a look.

 

Really good diagram I like this - really helpful.

 

Thanks for the info John

 

Update
It turned out to be the pressure sensor which my local garage changed - now working ice cold. Thanks all for helping.

 

All up & running again ... cool breeze as they say ...

 

I had the same problem 05 gtc. One day ac just stoped blowing cold. Compressor would not kick in. After some diagnostic, urned out that cabin temperature sensor was bad. It’s located next to gear shift. Looks like little oval mesh. Bought used on eBay I think was about $70 took 10 min to replace. As soon as started car, heard compressor kick in and here comes ice cold air.

 

The ac went out in my 04 GT. I was getting ambient air from the vents. When I checked I was reading too much R134A. I then ran my VCDS and got an error code in the HVAC. Sorry didn’t save the codes. Cleared the codes and ac kicked in. Checked the R134A and was near the low end. After topping up now getting nice cold air.

hope this helps someone.