Wii MotionPlus won't connect to my remote?

Sorry for the lack of details, I lost my triwing a while ago so I haven't been able to open it up yet. I just bought a new MotionPlus accessory so my family wouldn't have to share one remote, but when I tried playing Wii Resort but it wouldn't connect. I compared it to my known working one, and it looks fine on the outside, just a little dirty.

Hope this is in the right place, I couldn't find a teardown or anything for the MotionPlus.