XSeries-forum

I’d be gutted if someone did that to me. Will make you forever wary of garages and mistrusting the vast majority of good honest mechanics.
On another note I now at last have reliable a/c in my 28 year old car. The moral of my story is don’t give up, it only took me 28 years.

Have a quick look (search) on Xoutpost - there's a ton of A/C info and expertise there.

There are a number of issues that can cause the symptoms you have. I guess at this stage you can't rule out anything that the previous indie said he did, so that means going back to basics.

The original issue was A/C cooling on one side only? That could be (as has been mentioned) either an air control flap or a heater valve.

Now the A/C doesn't cool at all?  That could be two failed air control flaps or two failed heater valves (hey, it could happen!) or something in the A/C itself.

There a many conditions that lead to the A/C not engaging. The aux. fan must be working or the DME/DDE will lock out the A/C operation. Various other system checks in the A/C system can also lock out operation if anything fails.

Finding the issue will require a coherent testing plan, starting with verifying the air control flaps are operating as expected and that the heater control valves actually shut off when commanded to do so.

Start with the car's engine warmed up, on a cool or cold day. Set the recirculation to Off.

Set the centre front vents to warm (three red dots), set both side temps to something like 20DegC. and set blower speed to somewhere near the middle.

Get warm air out both centre vents? If so, move on. If not, you have heater issues or air control flap issues.

Now set both side temps to 16DegC and move centre air vents to cold (three blue dots).

Get outside (cool or cold) air out both vents? If so, move on. If not, you have heater issues or air control flap issues.

Now turn on the A/C (snowflake button) and enable recirculation.

If A/C kicks on but air temp doesn't start to drop, then you have heater issues or air control flap issues.

If A/C doesn't kick on, then the issue actually lies in the aux. fan or A/C system.

Full testing the aux. fan requires a laptop and INPA/DIS etc. INPA can turn on the fan directly, confirming the operation and control of the fan. You may also see the fan kick on briefly at start-up (but I have never caught mine - and I've checked) or when the A/C is engaged but this "test" is unreliable as other factors (aside from a failed aux. fan) can cause this "test" to fail.

If the fan passes this test, then you can be sure that the problem lies with the A/C system.

I wouldn't touch an E53 A/C system until I had confirmed ALL of the above.

And if you find a fault in the tests above and subsequently fix said issue, that doesn't rule out the possibility that there is ALSO an A/C fault... ::)

Wpoll...great detailed reply, thanks.

Fault is def. with the system.

Half of system worked, had it regassd. cool from BOTH sides now but cooling fan didnt come in.
On one of our great hot days this summer, I was in a traffic jam when car engine coughed and aircon stopped working.

I believe compressor blew and subsequently losts gas,

NOTE ******(I dont know why the aircon worked without the cooling fan kicking in in the first place because if it don't work, the clever BMW system should prevent the system from running!!! but it did.)*****

So, no system cooling and the pressure must have got too high and it blew compressor and possibly seal in the system.

I bought a compressor and fan off Fleabay and had them fit but still  no aircon.

I took it to the guy who ripped me off ( the BMW specialist !!) and he pressed the fill valve and there was no gas in the system so even though the new compressor and fan had been fit and the system regassed.....the gas leaked out.

That was the start of the great rip off and I was paying cash in hand to a guy who was lying to me and not even touching the car....just saying he was.

So I reckon the vents, flaps valves control is all OK...It's a fault in the heart of the system involving the compressor, fan or gas.

This car has been a nightmare, why it's lable the ultimate driving mchine is beyond me.

I need someone with the experience, expertise and technical knowledge of how the system works, with appropriate test equipment and lives within  a 50 mile or so radius (of Doncaster) to help me.

Thanks for taking the time to reply to me in such great detail though 

Hey did you manage to sort. I'd go see Granville in Halifax if you are nearby. You may have a wiring fault or a leaking condensor