I just bought my first ever ATV. Bought a 2000 Sportsman 500 for $400 and it needs a little TLC. I have replaced the key switch and repaired the recoil. Installed a new gel battery since the old battery would not hold a charge. When I turn the key to the "ON" position the green light comes and the cooling fan starts running. I have read on here that is not correct. Also when I push up on the start button the fan goes off and the green light goes out. The starter does not engage either. Does anyone have any idea where I need to start looking for my problems?

Any help for an old fart like me?