Hi, First check all your connections. If they're ok, Is one of the grips loose on the bar? That was the problem with mine. Both grips work in line together. If there is a break in the current, neither side will work. If the grip(s) loosen and twist on the bar, it will usually in time, break the wires inside the grip. You can hook jumper wires from the grips to a 12 volt battery, they will heat up if all is good. If not it is bad. Also, do a search here(TY.com) on this subject. Alot of us just went through this. Let us know how it goes. Soc