I think I know the problem, but I’d like confirmation.
On my wife’s truck (the above mentioned vehicle) the wipers have suddenly stopped working. The symptom is that you can manually move the wipers around and around.
This tells me that either the inside of the wiper arm is stripped or the spline on the wiper spindle (probably not the right term), but I’ve not sorted out how to take off the wiper arm to check.
Is there an easy fix? Or at least one I can do myself?
Yes, and the word of advice to the wife is to not turn on the wipers when they’re iced down. 
Some wiper arms have a nut under a plastic cover on the arm, and some have a bayonet type attachment below the wiper arm. From what it sounds like the splines on the wiper arms got stripped out when the wipers were frozen in place when they were turned on.
Tester
That plastic cover Tester mentioned just pops up with a screwdriver.
The real reason I posted was to suggest that you can get new arms far more cheaply at a parts shop than at a dealer. Generics are about $15-$20, and if they don’t have one for your vehicle on the pegboards VIP can order one out of their “crash parts” catalog.
Well, we’ll see if it lasts as I suspect the splines are stripped out. What I found out when I took off the cover was that the nuts on both sides were very loose.
I tightened them and under light duty (ie, I hit the lever to put fluid on them) they both worked.
However, since I could freely rotate them before tightening the nuts I’m pretty sure they were stripped. At least she should be able to wipe the rain off and it’s a temporary solution until I can get replacement arms.
Thanks for your help - it was realizing that the cover was a separate thing that got me going in the correct direction.