I installed the heated grips on my 05 CVO ElectraGlide and they were fine for a month or so. Then when I went out for a ride one morning found the battery DOA. Further investigation showed the grips to be on with the ignition off.
To make a long story short, when I pulled the left grip off, it had about an ounce of water inside. I think the water probably shorted out the switch inside and left them in an ON condition. If I turned the control on the grip to off,,they would turn off, however if I left the grips on heat and turned the ignition off, they would still heat.
I have read a few posts on other boards about the water problem. I will try the grips again now that they are dried out and if the switch inside the left grip isn't fried, I'll use some silicon in an attempt to cure the water problem.
I had a set on my 02 Ultra and for three years they worked perfectly.
The next solution is to try some grip heaters that are common for snomobiles that simply drop into the grips and have a switch for on, off, high and low heat. Supposedly for about 30 bucks or so.
Tom