Hi Dave,

Thanks for the detailed reply.

My 945T is a 93 and I suspect the clockspring is open.
Tomorrow AM I'll try to measure continuity in place between the two connectors
which should verify it's busted.

There's one wire to the horn buttons from the clockspring and brush,
apparently the return ground for the horn switch is through the steering column. Is that right? It's unclear to me how that 2nd leg is connected.
The wire goes to the central casting of the steering wheel, but how is the casting grounded? Is the steering linkage a reliable ground?

I've found that the clockspring p/n is 9140587 (old nr 3516420)
Tomorrow I'll check a few local places to see if they have it or order online.

There's a Volvo TSB for clockspring recall for some AWD models that should have been handled by the dealers.

That's scary what happened to your wife with the airbag punching her in the face.
There's a good reason to avoid hard plastic coffee mugs while driving.
I wonder what happens when the air bag deploys when you're swigging coffee from a hard plastic cup?
Wearing eye glasses is another problem area.
I wonder how many people are injured or killed by air bags?

Where is the 900 series clockspring install data from Volvo? Could it be in a TSB?
There's a nice AWD clockspring write-up here that should be similar:
https://www.matthewsvolvosite.com/v70-clockspring/

Cheers, Bill