Electrical question

400 polaris 2 stroke. 1999
I have manual, so don’t post telling me to buy one..
Problem is, changed rectifier because old one had melted hole. I have no neutral light but my revers light works. My awd does not work, fan does not work but my rad pump works. I have no battery, I keep dead battery connected to keep my lines from bouncing around and touching frame etc.
I changed main fuse.
So the other day I jumped my atv with truck and used electric start. Worked fine. Still no other electrical including lights. Were do I begin or do I need battery?? Could have all my lights actually blowen include the awd light? Just not sure wtf is going on. Btw manual is useless in this case.
Any help ! Thx