My daughters buyang atv was working fine today while she was riding. But after she turned it off to come in the house it won't start. i thought it was the battery but the alarm works. Usually the lights work when the ignition is turned to the on position but not now. Another thing i done was pulled out the fuse and checked to see if the alarm worked but it didn't. So i'm wondering if its the ignition switch thats gone bad. Any ideas??

 

You're right when you say the lights should work with the ignition switch on, so this is a good clue.

The power from the battery positive terminal goes through the fuse, then on to the ignition switch. When the ignition switch is turned on another wire is connected onto the fused battery power which then goes to the headlights and brake switch.

The alarm is wired to the fused battery power before the ignition switch.

Thus the ignition switch is suspect (as you surmised already). Take a meter and measure the voltages on the ignition switch's four wires:

1) one should be +12 volts all the time
2) one should be +12 volts only when the ignition switch is on.
3) one should be grounded all the time (use the ohmmeter function [in ohms] to verify this).
4) One should be grounded only when the ignition switch is *OFF* (open when on). Again use the ohmmeter to verify this.

The above completely measures the ignition switch operation, though only steps 1 and 2 are relevant to your particular problem. You are trying to figure out why you aren't getting battery power to the brake switch /starter interlock (and then on to the starter solenoid activation coil).

It could also be a bad wire to/from the ignition switch. So keep you meter handy.

Here's another tack: Put the quad in neutral. Set the parking brake. Short the solenoid terminals together with the shank of a screwdriver and see if your starter turns. If it does then this verifies your battery is fine.