Follow Kermit's advice re battery.
There is a connector to the steering wheel airbag just below the rotary coupler, but my bet would still be on the coupler they are a common failure item.
You can get at the connector without removing the steering wheel, but not the rotary coupler. Getting the wheel off is not difficult, airbag assembly off first, screws at the back of the wheel, you will find another connector in the wheel which will allow you to completely remove the airbag assembly.
On NO account put a meter across the airbag connector unless you want a face full of bag If you disconnect the connector below the column plastics, you can test the rotary coupler with an ohm meter (DVM)