You need the wiring schematic from the service cd's to understand the system.

The control module I switched from side to side and the passenger side extender started working. I cut the duff module open and found that moisture corrosion had rusted the spring on a contact coil. I replaced the spring with one from a generic automotive relay (aftermarket headlight relay, electric fan, etc.) and epoxied the case back together. I re-installed back into the original location to confirm it worked. My passenger side now worked and I knew the drivers side module was good.

Since I now knew the drivers side module was good I checked for lack of signal to it. I diagnosed the seatbelt switch with a wiring schematic from the service cd and multimeter. The seat belt receiver can be disassembled. It was a matter of a contact tab that had gotten hot and smoldered it's way into the plastic until it no longer made contact. I fixed the plastic with epoxy, re-installed the tab and re-assembled. Two years later my extenders still work fine.

Jorg