Fixed airbag warning light...3rd times the charm.
 

My '98 had the airbag warning. Autel MaxiDiag Elite identified "passenger buckle."

1. I decided to try DeoxIT on both driver and passenger seats. Sprayed into buckle and plug connectors. Reset code with MaxiDiag. 1st time passenger buckle was used it came right back.

2. Pulled seats back off and removed ground wires. Wire brushed them and applied conductive paste. Same error code.

3. Pried open passenger buckle cover and took a closer look at switch mechanism (this breaks pins in cover.) It uses an enclosed switch with plunger and two exposed resistors that are used for the resistance ladder. Could only see one spot where one might be able to get DeoxIT to penetrate inside; the plunger that is actuated when the buckle goes in. Doused it good and cycled buckle a few times. That didn't do it so I soaked it more and rotated the buckle into different orientations to allow the liquid to circulate inside the switch. That did the trick! Superglued cover back together.

Hope this fix is good for a few years. If it comes back I'm going to just buy the $80 buckle fix kit.

P.S. As a hilarious and somewhat sad aside, when removing the driver seat I found the cigarette lighter plug the P.O. lost....then another one under the passenger seat. Then a plastic lighter plug cover that he must have bought after losing both lighters.

Isn't it fun to get something fixed? Good job!
How do you like the Autel tool? lt looks like it'd be worth buying.

I like the Autel. It is the most versatile scan tool I've seen (works with the most vehicles, from the most countries.) It can't check everything on the Boxster and can't do as much as the Durametric Pro (if the Durametric actually worked on my car.) Apparently, Durametric made a change in their software to protect copying that made it no longer compatible with some versions/years of cars. My '98 was one. They don't offer any solutions so I can't recommend their software.

The Autel was able to diagnose and reset both the airbag and alarm system faults. The alarm system fault did not come back. The airbag did, until I made the fix. The Autel detected an ABS fault and instrument cluster fault but couldn't clear either of those. I have no idea what could be wrong with the instrument cluster. It works perfectly.

Good job! I too have an Autel, a Maxi-Diag MD702 that I bought to clear the airbag light and it worked. The airbag light was on when I bought the car and it hasn't come back on since it was cleared. I guess I got lucky, I didn't have to mess with the seat belt buckles.

The only thing concerning, with the MaxiDiag was there were multiple versions at different prices. I wasn't sure if all of them would work with the airbag for the Boxster. I ended up getting the MD802 "Full system +ds" which was over $100 more than the less expensive one.