Hungry for muff eh? Fancy a bit of curly neoprene between your incisors??
the chap that does work for me on my bikes is going to wire them into the lighting circuit cus some **** switched them on when i had stopped for a break on the motorway and flatend the battery
When I've been out on cold days what I've noticed is they keep the inside of the hands nice and warm but the outside of the fingers etc still get cold.
If yer only using the lighting circuit as a switch,(via a relay) it should be fine.
AFAIK,there is no accessory socket on the T.Just feed the grips directly off the battery,through a fuse and break the supply with a relay.The switch side of the relay could come off the lights.That way the grips will only work when the ign is on.(Think thats right.)