OMG, so after a ton of troubleshooting;
- I pulled off the steering wheel (had to buy a set of 5-point torx bits and a steering wheel puller to do it) and took off the column switches...
- I tested the switches as best I could with my multimeter and they seemed to work as I expected and I couldn't see any obvious damage like in that Territory video.
- I tested the continuity of the wires from the plug that the column switch plugs into, right to the plug that the wiper motor plugs into... all good.
I doubted the
BEM being the problem, since I wasn't having any other issues with anything else controlled by the
BEM.
After doing all this, I decided to do the thing I probably should have done first; check that the new motor/linkages that I bought off ebay weren't dodgy.
I pulled off the connecting linkages with a flathead screwdriver and tried the motor on it's own... It worked just fine, turns out the driver-side wiper socket/sleeve/whatever is completely seized, which incidentally was the exact same issue I had with my original one ��
https://youtube.com/shorts/rSdGL_nVh6Q