Hmmm, I have heat shrink over my left handlebar, two layers of it. there is still a notable difference between left and right grip temps so the theory of thicker grip material is a possibility.
So I bought a BMW rightside grip and put it on the left side, remember I have two layers of heat shrink on that side, well the left side is still cooler than the right.....Hmmmm, checked the wiring again and all is as it should be.
I have the Symtec by the way.
Now I an wondering what would happen if I threw on another grip heater element on that side....Interesting project in the works....I have a spare used set to tear up.
I think the aluminum handlebar makes one hell of a heat sink. The right side not only has the plastic throttle tube as an insulator but also has an airgap between the handlebar and the plastic throttle tube....might be why the right side stays hotter.