Hi, welcome. Pop over to newbies and introduce yourself when you have time. Fuses are not fitted in the negative lines. Are you sure it is in the negative? If it is a fuse and is glowing red something is pulling far too much current, or the fuse is too small. Without a circuit diagram it is not easy to say what. If you are going to do work on the bike it would be worth getting a Haynes manual, that would have a diagram which would throw more light on the problem. Sorry can not be more help at the mo. Edit KC and KH seem to be similar bikes and have found a KH diagram. There is only 1 fuse and it is in the positive. Have a look at this and see if you can identify the part that is glowing.