thanks for the TSB moto!

 

Here is the interesting bit from Motorcarman's attachment:

There are various root causes but the design and quality of the printed circuit board
within the cooling fan module are the most significant. The NAND gate used in the
circuit is defective causing multiple failure modes, this can result in high engine
temperature and overheating due to the cooling fans not operating.

A change has been implemented in production from VIN C91720. On these vehicles a
‘Philips’ printed circuit board has been used that has a modified voltage spike protection
strategy.

So, that NAND gate, heatsinking, and voltage spike protection might be the way to go.

Maybe a modification to remote mount might help to keep things cooler.

 

So what I am wondering is if I splice the power connectors for the fans to the battery via a switch which I put in the dash, would I run into any problems? I need to be able to gain at least functionality of one fan so I don't overheat until I find a fan controller?

Thanks for reminding me to buy the philips brand controller plums

 

That was really for Thermo and his ruminations, but the tsb is older so probably anything in the dealer pipeline is the new design.

You need to know if the fan motor is a regular 12VDC motor.

If you determine that is the case, then there *should* not be a problem to supply it with 12VDC. That is entirely at your risk.

But, the current draw may be such that you should consider: switch + relay + fuse

 

disguay, the blower motor in the dash can pull up to 25 amps as I recall. So, a simple switch is not going to be possible to use as finding a 25 amp switch is difficult to do in a 12 VDC rating. Also keep in mind that the switch will only allow you to either have the fan off or at max speed. If you want something in between, then it will make things a lot more confusing. If you want to know more about this, let me know. You can make a variable speed control like what the car uses, but then you have to make a pulse width modulator circuit and a high current switching circuit.

PLums, thanks for the info. I will keep that in mind. I am ultimately looking for a way to save others some money and as long as they can do some basic soldering, come up with a way to get them back on the road. So, we'll see what I find.

 

Would it be a smart preventative move to move the "fan control module" away from the heat area by extending wiring? Or, is there a temperature sensing function in the actual module that requires remaining in the stock location.

JTIS does not really show the area clearly, although the EPC might.

 

plums, the fan controller is directed via the ECM via a pulsed signal. THe longer and faster the pulse is, the faster the fan will run. So, the signal from the ECM is not a simple "Yes" or "No" signal. Hence why simply bypassing the fan controller isn't an easy option.

As for keeping the fan controller cooler, yes, you could move it off of the radiator a little bit. That should hopefully drop the temp that the controller is subjected to from around 200F to around something in the neighborhood of 130F (depending on the location of the final install). That should allow the components to last longer. But, only with diagnosing a failed module will this be truely evident.

 

So, to be clear, the circuitry between the fan motor and controller is not sensitive to distance within reason? (eg. 2 feet of extra wire)

BTW, how about checking out:

https://www.jaguarforums.com/forum/j...69/#post370023

 

Found an alternative bandaid:

The Jaguar Drivers Club of Australia - Tecnical Tips, Modifications & Questions

ok, it's got to be said ... there's more than one way of cooling a cat

 

So although you guys advised against it, I threw in a switch to just one of my fans and not to both of them in hopes to lower the amperage. I commute to and from work which is around 130 miles a day and about 40 miles are in stop and go traffic so I needed a quick solution while searching out a fan controller. When I looked at the fan controller I was a little astounded that it wasn't just a plug and play type deal. It looks as if the wires going to the fan control relay are connected not with quick release connectors like I thought, but actually hard wired into the board of the relay. Is this right or am I just not looking at the right thing under the hood?

 

PLums, yes, the distance of the wiring will not be affected in this case. Adding in up to even say 20 feet of wiring is not going to affect anything, especially the control signal between the controller and ECM. The "limiting factor" really is the gauge of wire for the main power to the fans. By using too small of wiring, you are going to end up with a large voltage drop, leading to the fans running slower.

As for your questions about the coolant voltage, this deals with a completely different topic. By having a larger voltage in the coolant, this is going to lead to galvanic corrosion of metal parts, especially those in the radiator due to the materials used in making of a radiator and their thicknesses. IN galvanic corrosion, the hihger the voltage, the more current that can flow. With more current, you have more "eating" of the metal, leading to pin hole leads and in general destruction of the metal components. THis is where using all the same metal throughout the whole coolant system is key as galvanic corrosion requires the use of 2 or more different metals.

 

Thermo, I seem to have 2 failed modules. First one failed completely, fans didn't run at all. I found a module via internet at a CA recycler and installed it. Both fans run fine on high speed but only one fan operates on low speed, and Jag dealer just told me this was likely the reason why my A/C doesn't cool. Is that possible / likely? Is there a way to confirm?

I'll keep my eye on this thread and once I find a 100% working module (or give up and replace the whole fan assembly) I can send you both of my defective modules if you still want them.

Thanks for your postings. They've helped me manage my maintenance expenditures.

 

X2002, once you get things straightened out, send them my way. Let me know how much the S&H is and I will send the money your way.

 

I found a box of Radiator Fan Cooling Modules in my 'pile-o-parts'. I don't have a car to put these in so I am offering these to the members.

See my 'for sale' advert!!

bob gauff

 

Thermo, do you still want old fan controllers? I don't have my 2002 X-Type anymore, but I do have 2 old fan controllers (and a new in the box water pump). Cleaning the garage out but hate to toss car parts in the dumpster.

 

X2002, sure, i will take them and do some more analysis to see if there is a common trend. I will send you a PM with my addy.

 

Maybe my finding(s) will be helpful:
https://www.jaguarforums.com/forum/x...x-type-103778/