Engine fan will not turn off
 

I have a 2005 X type 3 litre automatic AWD. The engine fan will not turn off when the engine is switched off, the temperature gauge is normal and the car runs fine, no warning lights on the dash. I had to disconnect the battery to stop the fan as I'm not sure what fuse controls it. I have had no issues like this before. Does anyone have an idea about what may be the problem.

Check the coolant level in the reservoir. If low, top off the coolant, then check for a slow leak, often at the nipples to the reservoir, the flat bottom of the reservoir or the water pump.

Graham, if the car is running hotter than usual, but not overheating the temperature gauge will stay where it normally is-just a tiny bit past halfway. Those gauges are not linear. More like pass fail. If your fans were staying on after you shut the car off chances are it was running hot. If you would have let them keep running eventually they would have shut off on their own. Like DW said, chances are the coolant is low and he gave the two most common reasons. I had both happen to me. If you own an X for any length of time you are almost guaranteed both of those things will happen to you.

Thanks for the advice, I will check both today

I'm back!...checked the coolant level when the car had been standing overnight and the engine was cold, it was a little low but topped it up anyway. When I re-connected the battery the fan started up again, I assume from that it is not related to engine heat but rather it is an electrical fault. Any more ideas before I contact a mechanic. Cheers Graham.

O check the next 3 things. First you can pull fuse #25 to de-energize the fan module, which will de-energize the fans.

I would be placing money that you are having a problem with the fan control module. What you can do is access the fan control module and find the white/blue wire on the fan control module. If you connect a multimeter to this wire and set the multimeter to measure DC voltage, you should get a voltage that is relative to the percent on that the fan is. If you are getting zero voltage (with the motor off) but the fans are still running, then that confirms a bad fan control module. If you are getting 12 VDC, then you are looking at either the motor running warm and the fans are running to help cool it down (but this should only take a few minutes at most) or you have a problem with the engine management computer (bad temp input or failure inside the computer). If your dash temp guage is still indicating normally, then you can rule out the bad temp sensor.
If you need a fan module I have 2 ready to be shipped. I do ship world wide. Shipping rates are low. Let us know what you find out. sometimes its just a bad relay that broke in the hot position.


Good Luck,
The Dr!

Thanks for the reply Dr....Fuse F25 in the engine compartment fuse-box is not used so I'm assuming it's not there. Fuse F25 in the passenger compartment is described in the fuse diagram as 5 amp (brown) On-board diagnostics...is this the fuse you are referring to. I'm taking the car to an auto electrician on Monday and will advise him to take your advice. If it turns out I need a new fan module then I would be interested in purchasing one from you.

Graham: I've purchased a few parts from Dr dome. He knows what he's talking about and his prices & shipping are very reasonable.

Attached is the wiring diagram of the fan control module in a 2002 X-Type (what I drive). Thermo says Jaguar revised the X-Type wiring in early 2004, so I don't know if this is similar or different in your 2005, but I'll offer it up and let other's comment.

In the attached 2002 wiring diagram:

WU is the white / blue wire from the Engine Control Module to the Fan Control Module. Per Dr dome, when the fan control module works properly, with the engine off, the fans should be off when the white / blue wire has a 0 volt signal from the ECM, and the fans should be at full speed when the white / blue wire has ~12 volts.

NG is the brown / green wire that supplies ~12 volts main power to the fans. In an '02, it's powered thru an 80A fuse F8 under the hood. Your '05 uses 80A fuse F40 under the hood. This NG wire in your car likely has 12 volts and high amperage thru a good fuse F40 since the fans run at full speed longer than you'd like.

WG is the white / green wire supplying ~12 volts to the electronics within the fan control module. In an '02 it's powered by an 15A fuse F37 under the hood. In your '05 it's powered by a 5A fuse F16 under the hood.

Hope this helps.

I will check the 05 wiring and make sure of the fuse. I have 02-04 and 1 05. Let us know what you find
Good luck,
The Dr!

DW and the The Dr...thanks for your help and interest, it would be great for me to find out what fuse is relevant to the fan in an 05 model as the owners handbook does not specify one. I suppose I could drive the car to the auto election with the fan on full blast.

Graham: I found the electrical drawings for the fan in your 2005 X-Type. The wires to the Fan Control Module are the same as my 2002, but the fuses are different:

Thanks DW, I have fuse F16 (5 amp) Radiator Fans Speed Control but curiously I don't have fuse F40, they only go up to F38. see diagram
http://ww2.justanswer.com/uploads/mo..._030901_52.png

Fuse boxes for my X Type
 

Thanks DW, I have fuse F16 5amp Radiator Fan Speed Control but according to my fuse box diagram I don't have fuse F40.. they only go up to F38. I tried to attach a diagram without success. Graham

Woops!

Graham: This post has the wiring diagram for your 2005:

https://www.jaguarforums.com/forum/x...4-25-a-152076/

Graham: In your 2005, under the hood the fuses go up to F38 when you look at the top of the fuse box. But......under the fuse box are fuses F39 (150A), F40 (80A - powers the fans), F41 (80A) & F42 (50A). See the diagram below. It's from Jaguar's 2004.25+ MY electrical guide.

We already know fuse F40 is supplying power to your fans, because they run; they even run too long! So F40 is a good fuse supplying plenty of power to the fans.

As Dr dome explained, the problem is more likely the circuitry inside the Fan Control Module, which has evidently gone bad and is causing the fans to be 'stuck' at full speed long after the engine is shut off. The test Dr dome proposed is this:
(1) Run the engine until it reaches normal operating temperature
(2) Turn the engine off. From what you describe, the fans will continue to run for too long & too fast after the hot engine is off.
(3) While the fans continue to run, pull fuse F16 (5A) under the hood. If the fans turn off when you pull fuse F16, then the Fan Control Module is working correctly. But if the fans continue to run after you pull fuse F16, then the internal circuitry within the Fan Control Module is bad and acting like a switch that's stuck in the 'on' position, Dr dome can perhaps help you with a replacement.
(4) If the fans turn off as soon as you pull fuse F16, then the Fan Control Module is working properly, and the next steps are to explore the ECU or temperature sensor as possible culprits.

If I have not explained this correctly, I'm sure Dr dome or another member will help us figure it out.
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If this picture is too small or too grainy, a larger copy is on pdf pages 13 & 14 (numbered pages 11 & 12) of the 2004.25 Electrical Guide pdf, link here: https://www.jaguarforums.com/forum/x...4-25-a-152076/

DW, I figured out from the electrical diagram (handbook) you kindly sent that the F40 fuse was under the fuse box and I also referred to the most recent diagram you sent, which was also in the pdf. I did as you suggested and removed F16 when the engine was warmed but it did not stop the fan so it seems the module is kaput. I sent a message to the Dr earlier today asking him about prices to ship another module, I'm hoping to hear back soon. Thanks for all your help, it enables me to be more specific when I throw myself at the mercy of the auto electrician tomorrow. God bless America. G.

Fan Control Module
 

Hi Dr Dome


with the help of DW we seem to have isolated the problem to my Fan control
module in the 2005 X auto 3 litre. You mentioned you have a replacement part, would you let me know the price plus postage to Sydney Australia and how I would pay you. Thanks GrahamJagX

Graham: Glad to be of assistance. You're doing all the work. I'm just calling plays from the sideline.

Suggestion: To save shipping costs, ask Dr done if you can buy just a fan control module from him & install it on your working fans. If feasible, should reduce the shipping cost.

Graham: Did you get a chance to check the white / blue wire from the ECM to the Fan Control Module, per Dr dome's suggestion? With the engine hot and off, and the fans still running too fast and too long, check the voltage in the white / blue wire. If it's ~0V volts, this confirms the Fan Control Module must be bad. But if the voltage is closer to 12V, then the problem could originate in the ECM or the temperature sensor.