Mk7 Aircon problem

[daipower]

Hi,
I have tried posting in the past, but never got the answer.
My Mk7 2.2 transit has aircon, turn on the engine and the pump starts for a few seconds then goes off. I have had it re gassed etc, all good, but if I bridge out the relay under the bonnet that controls the compressor it comes on no problems.
Any suggestions in plain to understand speak please, I would be eternally grateful.
thanks
Dai

[v8dave]

Try this,

Turn on the engine and allow it to idle for a few minutes with the a/c off

Set the air control to defrost.
Make sure recirculate is off.
Select lowest blower speed.
Turn the heat control to minimum.

Turn on the a/c

What does the light on the a/c switch do ?

[daipower]

I have been reading up on the wiring diagram of the aircon on my mk7 2.2. I am going to try changing the "Aircon cycling switch". Where is this located on my van and do I have to drain the aircon fluid to change it.
thanks
Dai

[daipower]

I bridged out the pressure switch which is under the van on the passenger front wheel, still the same. Bridge out the R10 relay, all works fine. I took off the expansion bottle and got to another pressure switch, not sure which one this is but it had four wires. I bridged out corner to corner and the clutch kicked in and pump came on. It rand for about 30 seconds and then went off.
I am ordering a new switch as the wiring diagram shows it as a slow speed cut off switch whatever that it.
Any thoughts
thanks
Dai

[v8dave]

Where are you getting your wiring info from ?

My copy of etis has some errors on the wiring information for the aircon !
Switch names and connector locations are not consistent.
There are two switches on the system, one behind the left headlight on a pipe and one below the same headlight on the accumulator.
One switch has four wires to it and other has two wires.
Both switches have valves between them and the working fluid in the ac system that should automatically close when the valve is removed.
The correct torque for both switches is 8Nm.

R10 is the ac clutch supply, if you bridged that out then the clutch would be permanently engaged. I don't see why it would stop after 30 seconds unless there is a safety valve in the compressor.

Have you had the pressure in the ac system checked ?
The compressor starting for a few seconds then stopping is consistent with a blocked orifice tube.

Edit:
found the system off pressure info. a test manifold connected to both ports should show between 4.1 and 5.5 bar when the ac is off
the high switch probably activates at 13 bar and the low at about 3.5 bar

[daipower]

Dave,
thanks for the reply.
The clutch kicks in on start up, and then goes off after about 5 seconds. If I bridge out R10 then it works fine. I am getting my wiring info from my Haynes manual, although I agree the names for the switches etc are not correct I dont think. I managed to locate both pressure switches, I took the one off under the wing and bridged out the two wires, the clutch responded in the same way. I took out the one above the wheel in the engine bay, the one with 4 wires and checked the wiring diagram. The diagram shows two switches inside, one NO and the other NC. I tested the switch and one was open and the other closed. I bridged out both sets of contacts and the clutch rand for about 30 seconds and then went off. I am guessing only one should be open or closed at a time so I have ordered a switch, but could only find a secondhand one, I couldnt find a new one which wasnt a ford one as they are £80 each.
ANY HELP greatly appreciated, switch should be here this week so will post the outcome.

[daipower]

New pressure sensor fitted, its still the same.
I have now put a diagnostic on it and it says P0480 cooling fan circuit malfunction, short circuit to ground or open circuit.
Any idea please, this is driving me nuts.
thanks
Dai

[blue estate]

There's a electric fan on radiator and that's not working so air con will not come on
Give the fan a spin I bet it's seized


Sent from my iPad using Tapatalk

[daipower]

I have two fans, both spin as soon as i turn on the air con.

[blue estate]

I have two fans, both spin as soon as i turn on the air con.

weird one then ?

[Altransit]

What is also weird is that my Mk6 with aircon has two fans, and the Mk7 has only one (on the passenger side), and that runs when you put on the aircon, but goes off because the compressor is not kicking in

[daipower]

Lads,
I think I have cracked it. I sat down with the wiring diagram after reading the posts on here. Some time ago I managed to buy a secondhand rad with twin fans and control box. I took the control box off that rad and tried it on my van, still the same problem. After a while tonight I noticed that only one fan was working which got me wondering if the box could see the voltage from that fan and in turn switch on the air con clutch. I got a battery and connected it direct to the van no joy, fan wasnt working. I then went to get the secondhand unit, I unclipped it from the rad and took it over to the van and plugged it in. Hey presto, aircon working again as it should.

So, if one of your fans isnt working, the aircon stops. Probably a check to start off with as its far easier to check than pressure sensors etc. I now have a spare rad with twin fans, the one on the right as you look at the van from the front isnt working, but the box of trick etc is.
Of note, the box of tricks is 940 085 00 and the original one was 940 043 00 in case your trying to get a seconhand one.

I hope this is the same fault for you guys, I am sure its not much to get a fan motor recond.
Let me know how you get on, this did my head in and I am so chuffed tonight.
thanks for the help on here
Dai

[Altransit]

Is there any chance of a piccy of your control box and wiring, as I'm a bit mystified as to why mine only has one fan If it's been previously removed, that will be the answer as to why mine isn't working

[daipower]

I dont have a pic to hand, but if you go on ebay and type on the part number there will be one on ebay, or search ford fan controller. Its a silver square box with one large connector on one side which is the live feed which you probably still have on the van, and on the opposite side is two black connectors, one for each fan. You will need a new rad which can take the twin fans and box, I have those here but one fan doesnt work. I think a fan repair or replacement is an easy fix as it could be motor brushes. They are difficult to get hold of and expensive, over 500 in Fords. My guess is that the fan itself is pretty standard size, maybe even the one you have on your van may fit. I can send you pics tonight as I have them all loose in my garage.
Dai

[Altransit]

This is my fan controller:-

FanController .jpg

FanController (1).jpg

FanController (2).jpg

Only one plug going in, and coming out



Fan Housing:-

FanHousing (1).jpg

FanHousing.jpg

So no smaller fan fitted, or ever has been by the looks of it.
Main fan cuts in and runs all of the time aircon is selected on the dials, turns off 30 secs or so after de-selecting aircon.
That's the fan that wasn't working on yours, wasn't it

So it does look as if my problem is indeed the compressor clutch, as the relay in the fuse box appears to work ok. I can't easily get at the power plug on the compressor to check for voltage, or to power probe the unit itself