Hello everyone. Want to save a few hundred bucks? After a few bouts of overheating, I determined that the fan control module on my significant other's X-Type has died. Buying a questionable used module is definitely not acceptable to me, so I came up with this fix. No, it's not perfect (see notes at the end), and these fans are LOUD when they're on, but for the price, I'll be able to live with it. Plenty of older cars use this system and it works just fine. My Honda has 235,000 miles on it and it's still working with all the factory parts *cough cough*. However, if it proves to be a bad idea on an X-Type, I will just shell out the ludicrous amount of money for a new fan assembly and module. If this fix satisfies at least one other person out there, I'll be happy.

Parts needed:
* $40 Zirgo Temperature Control Switch Zirgo ZFSWA - AutoLoc Radiator Temperature Control Kits - Overview - SummitRacing.com
* 2 40/30amp relays (pigtails optional). I had these laying around: PICO WIRING 5591PT - Pico Relay and Connector Kits - Overview - SummitRacing.com
* 1 large worm-drive hose clamp (to better prevent leaks)
* 12 gauge wire, several feet
* White pipe tape
* Assorted terminals - spade (one size smaller than standard), ring (two sizes), and female. I believe auto stores sell variety packs.
* Electrical tape and, optionally, heat shrink. Tie wraps too.
* Toggle switch (optional)
* Covoluted tubing (optional)

Tools needed:
* Phillips and regular screwdriver
* 8mm and 10mm socket and appropriate drive ratchet
* Soldering iron, solder, flux. Technically this is optional, but realistically it's not. :P
* Drill and bits (optional)

The temperature switch diagram can be found here: Zirgo ZFSWA - AutoLoc Radiator Temperature Control Kits - Overview - SummitRacing.com




Since I'm a Jeep guy, I had most of these parts available in my garage, so I don't know what the exact total cost comes out to be, but it's certainly cheaper than buying a whole new assembly, or even a used one. The Zirgo switch is $40, 12 feet of 12 gauge wire is about $6, relay and pigtails are about $6 each (two sets needed), the assorted terminals around $5, and the toggle switch is like $3. So somewhere around $60 total, and of course your time. This assumes you have soldering equipment handy, like any good nerd. This took me about four hours to do, but I went very slowly and had to spend a good deal of time determining where to place everything. Now that that's done, I could probably get it done in an hour or two.

Please read this entire how-to before starting work on your Jag, as this is only MY experience and what I did. You may need to tweak things a bit for your liking. It's a good idea to go through the steps on your car without actually touching anything, to make sure you have all the right parts. Disclaimer: I will not be held responsible for any errors, vehicle damage, missed work, or loss of life incurred by following my instructions!

Note: YOU MUST DISCONNECT YOUR BATTERY BEFORE PROCEEDING! WE WILL BE CUTTING NORMALLY-LIVE WIRES!

Step 1

Mount the bracket for the temperature switch and, optionally, the manual override (toggle) switch. I chose the valve cover. You will need to drill a hole in the bracket if this is where you decide to mount it. I used a simple metal toggle switch I picked up from my local auto parts store. Mount the Zirgo and toggle switch (screw in using only one terminal!) to the bracket before securing it to the valve cover. I was not about to draw the wrath of my S.O. by attempting to route wires into the cabin just yet, so I left the switch underhood. If the Zirgo breaks, or you just want the fans on NOW, in true Jag motoring fashion, just pop the hood and flip the switch!

I took off my plastic engine cover, so I'm not sure if this location will interfere with it. Check as necessary.
Note: Ignore the split ground wire in the photo below, I messed up.


Step 2

Install the sensor bulb: remove the upper radiator hose from the block pipe. Be sure to put some foil or something underneath to route the coolant that will spill out AWAY from the belt and alternator, or else you will end up with a grumpy squealing Jag and possibly a fried alternator. You can also put the sensor in the upper radiator inlet, but I chose this spot because it was convenient.

Insert the bulb into the pipe and then gently bend the copper tube back over the outside of the pipe. Don't bend it too tight or else it will kink and fail to function. Let me stress this again: BE VERY GENTLE WITH THE COPPER TUBE! Put the provided rubber gasket on the pipe, then make sure the sensor tube fits flush into the slot on the gasket. Wrap the whole thing several times with pipe tape. Wrestle the hose back on over the whole thing, and then tighten down the worm-drive hose clamp. Be careful not to stress the pipe - having two people push in opposite directions is probably the best way to go. If you have leaks, try rotating the worm-drive clamp to a different position - they do not distribute force equally.

Don't overtighten, but make sure it's tight and be sure to check for leaks. If I find any leaks, I may do this step over and use a bit of silicone RTV around the gasket. So far it seems to be holding up well.





Step 3

The single top screw that holds on the fan control module actually works very well for securing both of the relays, so this is what I used, plus the fan wires are right there! Mount the relays last, as you may have to remove the fan control module to get at the wires. Note: If you are using the Pico pigtails, the orange wire is unnecessary. To remove it, insert a tiny regular screwdriver into the center prong and push the tab down while pulling on the wire.

I believe each fan can pull around 30 amps max (thanks Thermo!), so I played it safe and used a single relay for each fan. I may be wrong and one relay may work just fine for both, but this gives me better peace of mind. The orange-green wire on the very TOP of the fan module will supply both relays (terminal 30). Double check by tracing it and its ground partner down to where it plugs into the engine harness. Since the fan module is broken anyway, and since it connects to the main harness with its own pigtail, I did not feel bad about cutting it. Splice and solder two wires (12-14 gauge) to this wire - these will be the RED wires if you're using the Pico pigtails, and they will go to terminal 30 on the relays - crimp and solder on the female spade terminals if you're not using them. Be sure to insulate this "big splice" VERY well - it is HOT at all times: that means when the key is off! Use heat shrink first, then lots of electrical tape, and even two or three small tie-wraps tied tight as can be to keep things from coming unwound (that's what I did).

*Note: I ONLY cut the 12v fan supply wire, everything else, including the two tiny ECU wires, were left intact and plugged in for fear that the ECU may receive screwy signals and throw all kinds of codes, lol.

I apologize for not taking pics of this, but I got caught up in the work and forgot.




Step 4

Snip both pairs of fan wires from the fan module. I was able to solder the passenger side (this is a United States car) fan wires without having to unplug it. The lower fan on the driver's side needs to be unplugged before you can solder because there's just not enough slack. Connect the "positive" wire from each fan to a wire that will go to terminal 87 (YELLOW wire on Pico pigtail) on the corresponding relay. On the passenger-side fan, this wire is orange with a green tracer. On the driver's fan, it's red. Solder the remaining fan ground wires to their own 12v wires and then solder appropriately-sized ring terminals at the end, then ground them. I chose to run them directly to the negative battery terminal, where there is a small nut that can be used to secure them.

Step 5

I don't like the idea of having even more constant power at the relays, as the instructions suggest, so I used switched 12v power from this terminal of R4 (oddly my car did not have this "accessories" relay installed) to power the fans only when the ignition is on. Splice the 86 wires (GREEN wires on Pico pigtail) into one 14-16 gauge wire, and use a SMALL spade terminal (this is not the standard size) to connect it to the R4 power source.

If you feel this is unnecessary, simply splice two more wires into the "big splice" in step 3 (you ARE reading the entirety of this how-to before tearing up your wires, right?). Since they only provide switching power for the relay, they don't need to be heavy gauge.



Step 6

Splice and solder the two wires from terminal 85 into one 14-16 gauge wire (BLUE wires on Pico pigtail). Crimp and solder on a female terminal and connect this wire to the "C" post on the temperature switch. If you want to use the toggle switch, you must run another wire from this feed over to the + terminal on the toggle switch (the side that isn't mounted and grounded to the bracket). You can either use a wire tool, or gently strip the sheath off the wire using a razor blade: circle the wire with the blade twice, about .5 inches apart, then gently run the blade between them and peel off the material. Wrap another wire around this and solder it, then solder an appropriately-sized ring terminal to the end that will go to the toggle switch +. Don't forget to securely insulate the splice with electrical tape or heat shrink!

Step 7

Connect the #2 terminal on the temperature switch to a ground - I used the same spot on the valve cover where the bracket is mounted. Use an appropriately-sized ring terminal.

Done! Now...

Make sure all of the wires are secure and routed neatly. It is a good idea to use some convoluted tubing to protect as much of them as you can. You can pick this up at any auto store.

Fill up the coolant tank, start the car, and adjust the switch per the instructions. Mine is currently set about 30 degrees clockwise from the fully "-" position. Finding the sweet spot will take some time, over a variety of weather conditions.

Purge the system of air (search for details) and continue to dial in the fan. Enjoy saving hundreds of dollars!

Bugs:

* I don't know if it's a coincidence or not, but both front windows' one-touch up feature stopped working after this. The rear work fine. I don't get it. Freakin' Jaguar voodoo.
* As I said, my main concern was keeping the engine cool. A/C may be a problem when moving slow or idling. So far, having the A/C on increases the temperature enough to kick on the fan after a couple of minutes, and I am not getting any hot air blowing at idle. However, if I can find a wire that supplies 12v only when the A/C is on, I will use it to run a third relay that will ground the temperature switch and turn the fans on when the A/C is running.

 

Blackcat, that is an interesting idea. The only part that I question is the Zirgo switch. By looking at it, it appears to be a wire wound thermostat. From my experience, they work great initially, but after awhile, the wire will develop some corrosion on it and will lead to a failure. A few wipes of the knob will fix it for a short period of time, but will reappear. It is especially a problem for those that live in areas where they salt the roads. Not to mention that you can get electronic ones with a relay built into them for around that same price. I have the electronic ones on my truck and have lived next to the ocean for as long as I have owned my truck (WA to HI to VA to MD).

Another option that I would need to look up again, but another member tore apart his fan controller and it appears that all that would need to be replaced is 3(?) transistors which can be had for about $5 on e-bay. Then it would be an easy solder job to put the new transistors in to the old module. BUt, I am wanting to get my hands on a failed module before I say that it is the only thing that needs to be done. So, if you have your failed module still and don't want it any more, let me know and I will pay for the shipping to have you send it to me.

 

Very interesting. I had a friend with a CJ-5 running this unit and it seemed to hold up fine - or at least I never heard him complain about it. Would you mind pulling up a link to the electronic one? If this holds up over the next few weeks, I will probably buy one to switch over to when the Zirgo breaks. I don't mind being the guinea pig, and my instructions are completely reversible and only cut up the wiring to the fan module (which is already broken anyway).

The module is still in the original location, I can pull it and send it to you when I get a chance, but it will probably be a few weeks before I'll have both free time and the car. Actually, I have an EE friend who may be able to open it up for me and check things out before I send it to you. He's really busy though, so I don't know if he'd bother - I'll ask him soon. Do you know if completely removing the module will throw any codes or cause other strange behavior? I would assume not, but since the one-touch up on the front windows happened to stop working at the exact same time I did this, I'm a little wary! I've built and tuned a few MegaSquirts, and replaced bad caps on motherboards and switches, but that's where my knowledge of electronics stops lol.

 

Niffty little mod and repair. I always wodnered about switching the radiator fant o electric witht hose universal kits. To ease the lood off the engine, increase constant cooling and save minute amount on gas. Saw it on tv. And online a few times

 

You must be a handy person , thanks for this write up . I hope you don't have a problem with your cooling system in long term

 

Black, check out this part: DIF 10090 Thermostatic Universal Dual Electric Fan Controller Ver. D

This would make all that you did into one simple package. Move over a few wires and all is done. The only thing you would need to do is add a wire from the A/C clutch to engage the fans whenever the A/C is used. But then, your system doesn't have that wire either from what I recall. Not a big deal as it is only really important if you are trying to use the A/C or defrost with the car sitting still and the engine cold.

There is no rush on the control unit. I'm going to be out of town for the next month on assignment for my job.

 

Well, it's been running for about two weeks now, and so far, so good! A few minor adjustments were necessary, and now the dial is sitting about halfway through its range. The fans come on when sitting for more than a few minutes, and turn off a few minutes later. On cold nights, they don't come on at all. The temperature gauge doesn't move at all (though I suspect it's a stepped, delayed "idiot" gauge that only starts to rise once the temp hits a certain point).

I'm hoping the weather heats up soon so I can really put it and the A/C through its paces. Will keep you updated.

*One problem I notice sometimes - heat soak will cause the fans to come on before you start cranking, and this unnerves me a bit because it puts a lot of stress on the battery. This might be because I placed the sensor in the actual engine rather than at the radiator.

 

One more thing I forgot to mention..... the one-touch-up feature on the front windows is working again. -_-

 

Thanks.

 

blackcat - thanks so much for taking the time n trouble to post this up.
Its a great write up with pics to show the method etc.....excellent.

I'm sure the method used will assist members in the future with the same issue.