[tcrist]

Does it only do this after running or with the key off and not has been running? If it is only like this after running then you need to check it out at your leisure (don't drive it of course). If it is just sitting there and has not been driven but the wire is hot to the touch, unhook your battery and get someone to look at it.

I would not be sure but it sounds to me like the alternator is putting out too much power to the gauge. Bad alternator maybe? As you say the wire is coming from your alternator then my guess is that you have an internal regulator and that might be bad. I am no professional by any means. I am sure someone else here can help better than I.

Terry