Mondeo Aircon Fan Question

[Roger...]

Mondeo 1.8 TDCI 2007

My aircon has been less than satisfactory for a very long time (tepid at best). I took it to a Ford agent about two years ago for a service. They checked out the system, checked it for leaks, and re-gassed it. If anything it was slightly better in that it was slightly cooler, definitely not what you would say cold. I have now decided to have another look at it. With full aircon on I have a low pressure of 30 psi at 65 degs F and the compressor always comes in when the aircon button is pressed on the panel. The pollen filter has also been changed. I have noticed however that the main cooling fan only runs occasionally but doesn't seem to affect the operation of the compressor. The indicated temperature on the dash panel once the engine is up to temperature is about 90 degs (needle in the middle) and never moves. I keep reading that for the aircon to work properly the cooling fan must be running all the time. As mine only runs occasionally what do you think would be causing this?

Roger

Edited May 18, 2016 by Roger...
spelling errors

[Roger...]

In addition to the above, I have just checked for fault codes and nothing is set.

Roger

[Barkingmaddog009]

I had a similar problem and bit the bullet and took it to a car electrical specialist who also is an air con specialist. (and only 5 miles away) my fault was identified after 12 hrs of fault finding to a fan switch wiring fault (bad earth), took ages to find and cost me £280 squid £230 to find the fault. No codes on the car other than fan switch fault but fan worked?? anyhow the fan system is links to the aircon and cools the aircon radiator when on. All working fine and used it all day today in the car 33 oc here in Cannock staffs.

[Tdci-Peter]

On 17/05/2016 at 7:32 PM, Roger... said:

I have noticed however that the main cooling fan only runs occasionally but doesn't seem to affect the operation of the compressor.

The main (radiator) fan should run all the time the a/c is on.

If it is not running, then the a/c condenser relies on car speed to get some airflow, and will perform badly if moving slowly.

I am not sure how the Mondeo fan works. On the Focus it has an electronic drive module. This unit gets power via a fuse and relay in the engine bay fuse box. This power should be present whenever the engine is running, whether the fan is running or not. It also receives a PWM signal direct from the pcm (engine computer), which controls its speed.

Sounds like an intermittent fan fault.