My 17.5 hp tractor will not start, I have had it 14 mnth. Initially when I turn the key it clicked but now nothing. I hooked it to my to check if it needed a charge but still nothing.

To answer this correctly we would need the model of the tractor.

But, here are a couple suggestions in the meantime. Check to make sure that the fuse is still good. It is typically located near the solenoid. On most Craftsman mowers that is just behind the engine under the battery or fuel tank on the right side as you are sitting on the mower. If the fuse is good then you either have a cable problem, a battery problem or a safety switch problem. You say you hooked it to something to see if it needed charging. Try jumping it right from a car and see what happens. Just don't leave it hooked up too long. Try those things and re-post what happens. Include the model number.