This kinda stuff sucks. You can read up on tips for findings shorts for days....but heres a couple things to try and think about...
Find out everything on that circuit and careful inspect the device itself for signs of damaged/corrosion. Failing that, shorts like to occur where wires are moving/bending regularly, like where they run through the door jam, rear hatch, or around the seats. Since you're getting an airbag light, and this thing likely has side impact bags in the seats, I'd take a good look underneath the seat to see if the harness is getting caught in the track....Or even move the seat around and see if that changes anything.
It hasn't rained in weeks, but have you taken it through a wash? Maybe water got in somewhere it shouldn't, check for wet carpets, headliner, or water in the overhead dome lights.
One thing I sometimes do (usually with the British stuff) is print a bunch of wiring schematics, lay them all out and using colored pencils trace back each wire from the known commonality (in this case the fuse), then go back to the car and check each connection/component along the way. It's tedious and frustration and I hate it. lol
Oh, and did you buy fuses from CT? If so, thanks for your support
