Air Bag Warning light

This is the second time I've had this problem.

I installed an inverter under my driver's seat. When I was finished, the air bag warning light came on and stayed on.

I eventually took it to the dealer where they diagnosed one of the plug pins was bent and not engaging. Okay, I might have done that when I reinstalled the seat and plugged everything back in. They fixed it by "straightening the pin."

Well little while later, my inverter stopped working. Volt meter told me I was getting power going in to it, so I had to pull the seat again to trouble shoot. I grounded the inverter to a seat bolt, which when the dealer fixed my air bag light, they never bothered to reinstall my ground. They just pinched the cable under the seat. It stopped working when the cable wiggled out.

So now that I have my inverter working again, and seat reinstalled, my air bag warning light is back on. I checked out the plugs, and they look perfect.

Anyone else have this problem? I'm in no mood to pay the dealer to fix this again.