'00 SS... the air bag light has been on since the PO (my brother) got the car about 2 years ago. I had the cabin flooding issue which I've already taken care of thanks to Chibi's post. That said, what are the chances that the problem is something other than a water-damaged air bag module? Can the module be tested somehow to see if it's bad? There are a couple of salvaged modules on eBay with matching numbers but I'm hesitant to get a used one because of how common the flooding issue is but I'm not dropping the $500 the dealership wants for it. Any advice is appreciated.

 

Get a scan to see what codes the airbag light is throwing. Then once you identify the problem you can go from there.