I have a 2002 X-Type 2.5 with a new A/C compressor that still won't blow cold. I paid my Jag dealer to diagnose, they noticed one of my fans doesn't run on high and stated that was "probably" the reason my A/C wasn't kicking in. Can anyone confirm that my fan control module could be causing the compressor to not engage?

I am on my second fan control module, this one came from a junkyard and I installed it when my original stopped working (fans didn't run at all). Here is how my fans currently behave:

1) Cold start, A/C turned off: Fans do not run at first. Then as car warms up (takes a long time, even in Houston heat) the passenger side fan kicks in on high when the temp gauge reaches 1/2 way.
2) Cold start, A/C turned on: Both fans run slow, and tend to start and stop a few times in the first 2 -3 minutes. Then the passenger side fan kicks into high and the driver side fan stops. In this case the PS fan is running on high even tho the engine is still cold (temp gauge still in the "cool" range, way below 1/2 where the fan kicks in on high with the A/C off).

The car maintains its engine temperature rock steady at 1/2 way on the temp gauge in all driving conditions.

My Jag dealer didn't nail down why the A/C wasn't cold, just stopped with the statement "you need a new set of fans before we can go further. New fans might get the A/C to work, but we can't guarrantee it".

I've seen a lot of very knowledgeable discussion on fans and the ECM in this forum, but none with symptoms and a question exactly like mine. Would appreciate any feedback I can get, but especially with regard to the following: 1) Do I need another fan module, or is it possible there is another underlying cause (like bad data from the ECM) 2) is it likely replacing my fan module will fix the A/C issue, and 3) suggestions for further tests I can run. Thanks in advance.

 

Hi: I live in arizona and experienced failure of my fan control module last summer. I too put in a junkyard one and all is well now.
I can't say exactly which fan runs harder or first on my '02, but my analysis of the wiring diagram suggests the AC brain gets a signal from the pressure sensor as to how much heat is being removed from the condenser coil. The same signal from the pressure sensor is telling the main ECU how big a pulse to send the fan box. If the main ECU sends a full-power command to fans based on info from pressure, and the box does not actually make fans go fast, the pressure sensor will only know the pressure is high (but not why) and turn off the AC system. My car did exactly that.
If either of your fans is coming on full in your dirveway with the AC turned on, and the AC soon turns itself off even with good fan movement, my money is on the pressure sensor or a freon condition but not the fan control box.