The power lead does have a fuse. There is also a relay with the wire's taped up next to the radiator. I don't have a switch for it just yet. I have just rebuilt my 32/36 weber and I'm playing around with jetting so just want to be sure that its getting the the right amount of spark. It would be easiest to run off the back of the alternator I think. Thanks for your replies. This web site and its members are awesome.