Join Date: Sep 2011
Location: Mishawaka, Indiana, USA
Year: 1982, 2001
Model: GL1100A, GL1800A
Here's (hopefully) the first page of the install instructions for Hondaline's heated grips, 08T50-MCA-102 (the entire 16-page document was too big to upload). Looking at the wiring diagram, I think there might be *two* problems here. First, the switch/controller may have failed in the on position, providing power to the grips. Second, there may be a short to ground between the two grips so that the one grip gets more power (and thus more heat) than usual, while the other grip gets no power at all. If the other grip had simply failed, neither grip would've worked since they're wired in series. What are your thoughts?
More bad news: unless things have changed since my switch/controller last failed in 2008, I'm sorry to say that the only way to replace *any* of the parts in this kit was to buy the complete kit, which cost me $302 back then. Still more bad news: a quick search on the part number turns up a lot of "no longer available" results on various dealer websites, which means that some experimentation with other heat controller units might be needed to get the grips back to working correctly, once the short is found & fixed.
Hope this was helpful.