That's awesome, I really like the idea of being able to adjust the heat with that much control. I'm currently shopping for a a vestIf you want to control the intensity of the grip or seat heat, then you might search Amazon for
PWM Dimming Controller For LED Lights or Ribbon, 12 Volt 8 Amp,Adjustable Brightness Light Switch Dimmer Controller DC12V 8A 96W for Led Strip Light By Zitrades
or click [HERE]
I use one on the grip heat as that gets too hot sometimes. I could use one on the seat, but since it already has a LOW/HIGH setting, I haven't done it yet.
The adjustment is under my left hand. I have the resistance box under the plastic, and yes, I had to drill a hole.
I've used the "Tone" knob from a Fender Stratocaster to replace the boring knob it came with. (see picture)
I didn't notice it when I took the photo, but it shows all the switches I've added. One, at the base of the left mirror, controls the "fog" lights in the front.
the two underneath the handlear control heated grips and power to the USB devices.
there's even a small hole in the plastic, up and left, of the two switches. This is one LED from a flat strip LED. It comes on when I flip the heated-grips switch to "ON". Oddly enough, it gets brighter or dimmer depending on how I twist the "tone" knob! Unexpected, but cool.