My 1998 XJ8s cooling fan won't shut off at all. I did try to disconnect battery and then reconnect but it still runs any advice? Thank you in advance.

 

The fans are controlled by the Engine Coolant Temperature sensor mounted in the coolant hose at the top front of the engine. Disconnect the electrical connector and see what happens. Fans should not run. If that cut the fans off replace the ECT sensor.

The ECT sensor provides input to the Engine Control Module which controls the radiator fan control relay module located under the front bumper, left side.

Let us know what you find.

 

Is this thing black, about the size of a small thin box of matches? Is it normally clipped to something or does it just dangle in the cavity behind the lower bumper cover near the intercooler radiator?

 

I found this thread entitiled "Overheating - Fan Control Relay?".
https://www.jaguarforums.com/forum/j...l-relay-41622/
Posting #7 Fan Control Relay Location was posted by johnleavitt

The relay is located just ahead of the left front tire in the space covered by the plastic skid pan. It is mounted to a spade connector and hangs down in the void infront of the tire.

Also Posting #2 - https://www.jaguarforums.com/forum/a...elay-rfcrm-jpg was posted by quadmanic

This part is called the Radiator fan control relay module in the DTC PDF file.

Gaudin Jaguar Parts website has cooling fan relay - retail price $91.75, discounted price is $74.54

I found the relay on British Parts co uk website - COOLING FAN RELAY - LJA6702AA. Here is the JPEG on the website:



Here is a better image file of it from an EBAY listing:




Jim Lombardi

 

Actually, the part is a smooth black matte finish plastic oblong wafer roughly the same dimensions as the remote key fob.

It is located near the draincock for the intercooler, but is not the ambient air temperature sensor.