2000 polaris magnum 325
#12
#14
#15
When you say you checked the grounds what did you do? A lot of issues can be linked to a bad ground that "checks out". There are tons of YouTube videos on guys re-grounding the front hubs and the 4WD starts working again. I have 2 uncles with 325 Magnums with now 4WD. As soon as the weather breaks I'm bringing them to my shop to re-ground the hubs, as this seems to be the root of most the 4WD issues on these wheelers.
Good luck!
Good luck!