jason weston

I had a similar problem on my 480. The heater pads are common across the range, and fairly easy to replace. The first part of the job is to identify which pad (seat base or seat upright) has failed. They are wired in series, so if either fails, neither works. The easiest way to do this is to get a multimeter across the terminals to each pad, and check for resistance. Whichever gives total resistance is the failed pad.

You then have to strip out the defective pad, which involves removing the upholstery from the relevant section of the seat. These are held in place with evil little twists of wire - so be careful.

Once you have removed the defective pad, you can replace with a suitable (either new original if you can afford it, or from a suitable donor, which can be any 400 series car), and as they say in the manual, replacement is the reversal of removal.

I did, however, use tie-wraps instead of the metal wire to resecure the upholstery - this worked fine, and was a lot safer on the fingers. Once this is complete, time to test by sitting in the car on a cold day, turning the heater on, and wondering why people ever buy cars without heated seats!!