Lincoln/Mercury Repair: 2000 Navigator heated seats not working, weekend mechanic, navie

Question
I am on the verge of repairing my wifes Navigator or buying her a new vehicle. If I could fix the heated seats, I am sure she wants to keep it.

Pressing the button on both seats lights the switch showing power to the switch. I verified power going to the switch on the connector underneath with a test light.
** What can a weekend mechanic do to assess this with a simple multimeter?
** What normally is the cause of seats not heating?
** Fuse is fine under the hood, what else to look at?
Really would like to keep this SUV. Help is definitely appreciated.

Sean

Answer
The good men at Lincoln have a stupid design on the heated seats. I spent $600 to have my driver seat repaired twice and now neither side works. It's because of a series of wires that connects the top heat pad to the bottom heat pad. When they take it apart you will see where a small burn is about the size of a nickle. So in the next few weeks I will spend another $600 to have both sides done. This time, I will supervise the repair and after they remove the skins I will do the repair myself. The money is in them removing the skins, labor wise. The fix is in the wires. There is only one wire that burns thru so fixing it is not a difficult job. If you have the gumption to remove the seat covers, the rest is easy. I love my 2000 Navie.