MA Mondeo TDci - AirCon Issue

Fordmondeo · 13-10-2014, 08:48 PM

Hi There,

I am writing this post in the hope I can find out some more information on the problem I have.

The problem is that the A/C compressor is not engaging until the engine reaches temperature and the thermo fan starts.
I have my own set of gauges to check refrigerant level and this is not the problem. All fuses and relays are ok. The A/C works fine when running even though they are a bit weak.
From what I have read the thermo fan is controlled by the PCM( might be called body control module) which is located in front of the front left wheel. I have checked the wire that goes from the PCM to the thermo fan it has a habit of failing (UK ford forum had the details), this is ok. I have done the self diagnostic test on the climate control module, no faults stored or active.
My next step is to buy an OBDII scanner and software to see if there are any faults active.
I have narrowed it down to the climate control module, the PCM or the thermo fan controller.It seems the signal from the climate control to turn on the A/C is not getting through to the thermo fan. All of these parts are expensive.

Is there any wiring diagrams available or a workshop manual on this forum?

I don't want to take it to ford as they would charge an arm and a leg to fault find and then just do the usual replace and hope that was the problem.

Thanks,

Luke

Deo · 14-10-2014, 06:26 AM

This is all I've found
http://workshop-manuals.com/ford/mon...ontrol_system/

Good luck!

Sent from my GT-I9305 using Tapatalk 2

**russellw** · 14-10-2014, 06:31 AM

Send me a PM with the details of which diagrams you are looking for as I have most of the recent ones in my library.

Cheers
Russ

Fordmondeo · 14-10-2014, 09:27 AM

Hi,

Thanks DEO that information is very helpful.

Russell I will PM you

Davehoos · 14-10-2014, 09:04 PM

does your mondeo have fan speed resister in the rad fan cowl.

I have come across early models that had no low speed and the compressor would not turn on. there is an issue with the air conditioning operating in very cold weather or during the warm up period.

often climate control vehicles wont allow the a/c till the heater core has warmed up, older cars used temp switches and modern vehicles use calculation from the PCM.

Fordmondeo · 15-10-2014, 10:37 AM

Hi Dave,

I'm unsure about the resistor. The a/c worked fine since we had it, have only noticed it not working the last few weeks. It could be the PCM as I believe the PCM controls the fan. The fan will only turn on when the vehicle is up to temperature, then the a/c will work as it should.

Davehoos · 15-10-2014, 04:55 PM

older euro fords have fan speed resister in the radiator cowl. like BF falcon.

Its possible that a electronic fan speed controller [digital-transistor] style is fitted even some PCM have this function cleverly placed inside. need a workshop manual to check-but it should be obvious.

expensive euro cars now run this inside the fan motor. you can tell by the smaller wires going in the back.
one car I worked on had temperature compensation circuit so when a rusty bearing got hot it tried to go faster.

Fordmondeo · 15-10-2014, 05:37 PM

Yeah having diagrams would make it easier but all good, its fun learning. With my radiator fan, there are 3 wires (2xthick, 1x thin purple) that go to a box on the back of the fan bracket. From this there are two outputs, mine is only using one, with only two thick wires to the fan motor. I believe the thin purple wire is the control wire from the pcm. I have checked continuity of this wire and it is ok. It seems that the pcm isnt allowing the fan to turn on until the engine reaches temp, then this allows the a/c comp to engage. I can cycle the a/c on and off once the fan is running so the signal from the climate control to the pcm must be ok.

will be getting a scan tool soon so will check for any fault codes

Fordmondeo · 16-10-2014, 07:57 PM

Had my OBDII scanner arrive today, so after messing around with some software found that forscan worked a treat.

Had DTC P0691 Fan 1 Control circuit low and P003A turbo boost control A position exceed learning limit.

From the fan DTC I'm leaning towards the fan motor being faulty so will test it when i have some time and look at chasing one up.

Is there somewhere i can purchase these fans or do i need to go genuine?

Thanks,

Luke

Fordmondeo · 20-10-2014, 11:24 AM

Ok,

Found a Fan for the car. After removing the front of the car to gain access to the radiator and fan assembly, I replaced the fan and cleared all DTCs. The car had been running without fault. I will re-scan again soon to see if the fault returns. I also cleaned up some of the ground points while I had access to them, the only part that has clean contact is the thread of the bolt.

Thanks for the advice Guys much appreciated.

Luke