All this talk of "shorts"... to people who know NOTHING of electricity or electronics, ANY electrical failure is a 'short'. But if you read 100/80's post, you will see that is simply not the case. If you take your car in for an electrical problem and the 'tech' starts talking about 'shorts' here and there - it means you are paying someone to do electrical troubleshooting that is not qualified to do so. Most of the time, it also means that you are at a dealership. (But even in the aftermarket-shop world, finding someone who can effectively troubleshoot an electrical problem is not easy.)

It sounds to me like a bad connection somewhere in the wiring harness, and can very likely be the switch itself (you know, the one in the console). Pulling the plate up and using a voltmeter on the leads is easy - see if you have power there first, this will direct you to:

1: A bad switch
2: No power to the switch
3: Power to and thru the switch is fine, problem is under the seat

This is the quickest way to gain a direction, otherwise, you are simply wasting time taking "shots in the dark".

The service manual (and all OTHER documentation) is available for download here at .org - I'd download the manual and look over the section on seat wiring, it is NOT all that complex. I have heard of seat HEATERS failing often, but the number of times someone has complained about the power seats is much less.