No heat on the left grip

[Boomer]

I was giving everything the final once over in anticipation for my first ride and noticed that I have no heat on the left hand grip only. I checked all the plugs underneath the handlebar cover and all seems ok there. Anyone have an idea where to look next. I had everything apart to put the new riser on but can't believe I mixed up any of the wiring.

 

[grader]

the wiring is in series so one grip not working should also kill the other. the power wire is yellow/red stripe runs to one grip wire. other grip wire goes across and plugs into other grip. last wire on second grip goes to ground. hope this helps.