Under the seat near where the battery is mounted. The hot or + terminal wire goes straight from the battery to the starter relay. In other words, begin at the hot or + side of the battery on your ATV and follow the red wire from the battery to the next electrical looking part that the red wire is attached to with a bolt/screw. That is your starter relay. Just a side note; your starter relay may not be a problem. It has fuses in it. Pull the two fuses and make sure they are not blown. Replace them if one is and then re-try your starter. There is also another box under the seat that has a group of fuses together, this is the fuse box. Check each one of those to see if one maybe blown. Only replace a blown fuse with the exact same size replacement fuse (example a number 3 or 5 or 7.5 or 10 or 15 or 20 or a 30 will be marked on top of a fuse. If a 10 is blown replace it with a 10 not a 20 or 30). Good luck & GOD BLESS.