Hello all, I'm new here and would love some help. I have done a lot of reading on this topic, but none seem to help me. Both fans come on full speed and are on all the time. Originally the fans were not working, I replaced the fan control module and the fans came on full blast. Pulling F16 fuse doesn't stop them. The power cable has 12v from both wires coming in. I read about some people having this issue with a thermostat, but that doesn't make sense to me, the fans are on even when the engine is completely cooled.

I was thinking about checking the AC pressure switch. I've looked through wiring diagrams, but can't quite determine what else in the engine can trigger the fans.

I appreciate any thoughts. Thank you!

 

Also replaced the coolant temp sensor. And to clarify, fans run with ignition off.

 

My X-Type had an old style FCM and the fans didn't run at all. Unused old style FCM's are no longer available, so, you buy the new style FCM and the adapter wiring. Been there. You can pay as much as you wish for what looks to be the same module in the same generic white box. Even the forum approved Gates module looks identical and works the same. The fans run constantly, backwards, blowing air forward. I found a used old style module and it works like it's supposed to.

 

@bigdiver Very interesting. When you say blow forward, do you mean towards the front of the car? Mine currently blow towards the engine (I assume that's the correct direction) Also, wouldn't the constant 12v be an indication that it is not the module?

 

Fan speed control arrives as a PWM (Pulse width modulated) signal from the ECM to the FCM on pin one of JB187 ( the white/blue striped white).
That square wave signal's on time varies between 5% and 95% on depending on the ECM's determination of what cooling is required.
Yes the ECM can hold the fans on if it deems the engine requires cooling after shut off, but if the fans are coming on immediately when power is applied to the car then you definitely have an issue.

You could initially try disconnecting the PWM signal wire (while/blue stripe) to the FCM to see if the fans stop. That will at least tell you the FCM is obeying some sort of command, even if the command is incorrect.
If the fans still run, then it is first and foremost a FCM issue.

 

@h2o2steam , that's a really great idea! I have both wires coming in at 12v the blue stripped one and the green stripped one. Will they not both run the fans? I guess I'm asking, if I disconnect the blue one, how do I know it's not the green one supplying a signal to run?

 

The White wire with Blue stripe is your fan control.
The White wire with Green stripe is a B+ supply line from fuse F16.
You should also have 12v on the Brown wire with Green stripe that is powered when your ignition switch is in the "11 " position.
That just leaves you a ground wire (Black solid) and four output wires (two to each fan).

Don't be tempted to apply a short to ground of the White/Blue stripe wire, as you could damage the PWM output of the ECM.
Disconnect the wire from the FCM to isolate any signal from reaching the FCM.

 

@h2o2steam you are amazing. Thank you.....I'm so freaking angry right now! I disconnected both green strip and blue strip wires and the fan still ran. Turns out on top of getting a crappy fcm (which btw was not the cheap ones, it has the 4 pin connector) I made a really dumb mistake. I was measuring my voltage from the green power wire to the blue strip and green strip one instead of measuring them to ground. So I tried it to ground and it looks like everything is working fine and I got a crappy fcm. Thank you so much!!