On the back of the 4 wheeler there is a relay switch that connects to the battery. It has a positive and a negative the positive comes from the battery and goes to he starter the negative on the switch should be grounded correct for the battery switch to work. So should there be a negative wire going from the battery to the switch.

 

You need a complete circuit for any electrical component to work. There is a wire going from the battery to the solenoid, a wire from the solenoid to the starter. The starter is bolted to the engine so the electricity goes thru the starter to the engine and then back to the battery thru a wire between the battery and engine. Now, the solenoid needs to be activated and carry the electricity from the battery to the starter, which is another circuit going thru the start button, ignition switch, fuses, etc.