HI Madbloke, sorry to hear of your woes.

I need a bit of info, the fuse that is blowing, can you see the colour of the wire. so i can work out from the diagram i have as to what could be wrong, may not be the switch

as for the fuel pump, the feed is a red /blue according to the diagam, black's the earth

the tenere had a problem in two areas regarding chafing wiring resulting in shorted out electrics

one was, with the seat removed an shiny allen headed bolt rubbed through the loom, rh frame tube. the loom is tight in this area and fastened with cable ties. i believe Darren 'gulg' experienced the fault

another was under the tank iirc going to the injector
http://www.xt660.com/attachment.php?...8&d=1282659240
info http://www.xt660.com/attachment.php?...8&d=1282659240

personally a good look at the loom to see if any rub through s have occured, you will have to remove a few components and the odd cable tie.

let us know of the colour of the fuse wire and get checking that loom!

all the best, bernard