With the speedometer unplugged, it acts the same as far as the 'Rev' light coming on, no AWD light, etc. It's up on a lift with the tires off so I can't run it without the speedometer.

 

This is a possibility, I have seen this twice. Under the front cover there is a large wiring harness that goes to the pod and handlebars. Several wires inside the harness were damaged and causing weird problems. They almost looked cut but from what I dont know. They were older atvs in your year range.
The other guys are right you need a wiring diagram to find some of these problems. It took me about 30 minutes to find this problem but without a diagram it would have been alot longer.