I've bought an XJR that needed love about a month ago, and I've given her loads of love. She runs great, pulls like a train, and I'm very happy with her overall.

Now, the rad fan stays on, even after the key is out of the ignition. Now, I'm sure this is a normal procedure for the car, as it's the same story with my Porsche Cayenne, but it turns off after five, maybe ten minutes at the most. I've seen things listing here about the coolant temp sensor being faulty, but gauge reads accurately, this has been confirmed with an infra red thermometer. Maybe I'm missing something really obvious?

I'd also like to know more about what this fix described here is referring to?
https://www.jaguarforums.com/forum/x...or-fans-62020/

 

A possible fault could be due to PN: LNA6702AB? I don't have a shop manual, where would this be? I've been told that it's behind the driver's-side headlight, but all i see there are 6 black modules.

I have tried unplugging the two temp sensors, neither of them stop the fan. So this leads me to believe that this could be the only problem left?

Update: Found this in another thread:
https://www.jaguarforums.com/forum/a...elay-rfcrm-jpg

UPDATE: I went to the car to move it onto ramps so I could get under it and access the relays up front. I started it moved it, and upon shutting it off, the fan shut off. The car fixed itself. Could this still be the same relay?

Unlocked it and the fan came back on. It certainly must be the relay?

 

Where's the best spot to order these little electric items? Any forum recommended website?

 

I always get the part numbers from the diagrams on Jaguar's official parts store - JaguarClassicParts.com - and then Google the part number. Surprisingly, Jaguar Classic Parts sometimes come out cheapest!

If you go to the Jaguar Heritage website, they will sell you a DVD containing all of the workshop manuals for your car, including electrical diagrams. This will come in very useful when tracking down spurious electrical faults. You can probably get pirate copies from eBay, but I didn't have a problem paying Jaguar Heritage the £30.

I had a quick look at my copy (Fig 07.1) and the fans and fan control unit are powered direct from the battery, so they can run on after the ignition is switch off. The fan control unit will either run the two fans in series (half speed) or in parallel (full speed) depending on the inputs from the temp switch and air-con pressure switches.

As far as I know, the over-temp switch, ECU temperature sender and dashboard temperature sender are all separate so it's quite possible for the dash to look OK while the ECU and/or fans are confused. Besides, the dash is an idiot gauge and it takes a serious over-temp condition to make the needle move. It usually sits resolutely in the middle for a wide range of engine temperatures.

 

Thanks for the input. The fan continues to run at full even when the temperature input has been removed completely. I've left the car to sit for a few days, and I'll get back on her today. Anything other than the fan control module that could be at fault?

 

AC pressure switches?