Fixed the wipers by returning the new parts and installing the old parts again.
Yeah, I know how that sounds, but that's how it worked out.
The wipers originally gave me problems over the summer, stopping in odd places, etc., which is very typical of a bad control module, very common on these trucks. So I bought a replacement module for it but when I pulled the old one out I saw that the issue was a contact on the module that was bent, and not making good contact. Since I had a new one I went ahead and installed it, and fixed the old one and saved it as a spare.
So when the wipers failed the other day I suspected the new module had died so today I pulled it and took it back to Autozone for a refund, then picked up a replacement reman motor with a module already installed, figuring I'd just swap the whole thing since the original was 11 years old.
When I got home though it was too dark and cold to start pulling the cowl off to unhook the linkage, so instead I just popped the original (fixed) module back in and closed up the motor. The wipers now work 100% again.
Now I just have to decide if I'm returning the new motor, or replacing the old one anyway since it's 11 years old and bound to fail eventually, probably sooner than later.