My wife's 2007 X-Type has heated seats. It had only the drivers seat as the full power seat and she wanted the passenger seat to be full power as well. I got all the power seat parts and installed them and it all works.

However the passenger heated seat does not work. It did work before the power seat change. I kept the original seat cushion which has the heater. I changed the seat back to get the power function.

To get started fixing the passenger side seat heater I pulled out the electrical schematics for the seat heaters; Fig 11.3 in the manual. It shows that the seat back is also heated. I had never noticed that, I always assumed that only the cushion was heated. That is the way it felt.

Curiously, the schematic shows the seat cushion and the seat back heaters and shows the connection between the two. However, it does not show a connector on that wire. If there was a seat back heater there surely was a connector since I did not cut any wires when I changed out the power seat components.

The old non-power seat back is gone so I can't get the heater from it (if there was a heater).

If the seat cushion heater is not working because the seat back heater is missing and therefore not completing the circuit can I just jumper over the missing circuit? There is a thermostat so the seat should not get too hot.

Now that the weather is getting cold I am getting noise from the passenger seat when we use the car. I need to fix this or the noise will continue all winter. ;-)

Pete.

 

Just jumping the missing seat back heater is not a good idea. Although the actual resistance values of the two seat pads is unknown, they are probably nor far off equal. If you miss one out, thus about halving the overall resistance of the circuit, the current draw will roughly double. It's doubtful if the Seat Heater Module (and maybe the wiring) would be happy with that.
Noisy winter coming up I fear!

 

Further to my last, if you go to SNG Barratt - The Ultimate Jaguar Parts Specialist and follow through the links under Find Parts, you'll get to Seating and then the seat heaters - squab and backrest ones are available separately. The one you want is £57 inc VAT.

 

I pulled the seat out to have a look at this problem. I can see now that there is a connector that is not connected. The seat back heater must have plugged in there.

I measured the resistance of the seat cushion heater: 1.3 Ohms and the temperature sensor: 12.7K Ohms. If the seat back heater has the same resistance then each of the two heaters will dissipate 27 Watts.

The problem is clearly the missing seat back heater. It seems that the only solution is to get the seat back heater and pull the seat back all apart to install it. Alternatively, I could get a 1.3 ohm resistor that can dissipate 27 watts.

Pete.

 

The seat bottom and back elements might not necessarily have the same resistance, so check the resistance of the seat back element on the drivers side to be sure, and then use the appropriate value resistor as a jumper, as you've already mentioned.

For info purposes only, a friend of mine did this to his Range Rover but used a paper clip rather than a resistor, and had no problems at all.

 

The only proper answer to all this is to bite the bullet, get a proper replacement seat back heater element, install it properly and enjoy the benefits.

I would advise strongly against paper clips except, maybe, in some get-you-home scenarios or testing some circuitry. Your insurance company will certainly see it as a way out of paying up in the event of disaster.

The idea of a ballast resistor putting out 27W (More at 14.4 v) brings to mind the recent spate of fires in Vauxhall Zafira caused by overheating fan motor speed control resistors.

 

I have the same electric heated passenger seat problem that you had, no heat to backrest, heat to the seat. Have not yet taken seat out to check connections. Did you manage to solve your issue and what were your findings please.
ERICMACX400