Hello to all:
Happy new year.

I have one last thing to fix on my xj8.

NONE of the seat heaters work on the car.
Drivers side, pass side, and both back seat heaters are not functioning.

I can hear the "click" when I turn on the drivers side seat, but I get nothing.

Where do it start?

I know that there have been issues with this, I just can't find one thread that addresses this.

 

There's several possible failure points to test. It sounds like the relay is engaging, but it's worth checking to make sure the switch inside is actually engaging instead of just moving, just basic relay testing. There will be a brown blocky relay under the seat, looks the same as the other relays in the fuse boxes.

Next, you can test the heater element itself. If it's cold enough outdoors (below 70f should be good, and out of direct sunlight to prevent warming the seat), you can check resistance across the heater relay output and heater ground (wherever the electrical guide says this is). Should be fairly low, I'd guess not more than a couple dozen ohms. High value indicates broken wiring somewhere past those testing points. I'd try and trace the wires that go between the input as close as possible to make sure those wires aren't bad.

Next, you could check the thermostat. I suppose these could fail, if it gets stuck open the resistance checked earlier will read high/infinite and you won't get seat heat. They open at a fairly low temp, so checking the resistance if it's 90 degrees out could cause a false failure reading. READ: https://www.jaguarforums.com/forum/x...-solved-44965/

The thermostat can be bypassed with a fuse, at the very least for testing purposes. With it bypassed, check resistance again across the heating elements. If it's still reading high then your elements are most likely bad.

 

Hello:
Is there a "main" fuse for the heated seats, or does each seat have it's own fuse?

It seems all of the heated seats are not working. Just wanted to check if there was one main, or one for each seat.

 

I bet 2002 is the same as "The 2001 Jaguar Vehicle Care handbook has the Right-hand and left-hand seat heaters fuse in fuse location number 18 (25 amps fuse) Rear compartment fuse box - right hand heelboard. It also shows Rear seat heaters fuse in fuse location number 8 (5 amp fuse) also in right hand heelboard fuse box." Check that little book that came with the car.

I would just test using control lamp that when I press the button and relay click - the power is delivered to the heat element wire(on relay), and would check the ground wire. It is a bit of a pain to reach under the seat for it. In my case both elements were blown(had black holes burned in them). So I ended up replacing elements with aftermarket ones. There are quite a few threads here on the subject, we all like our buts warm :-)