Hi, Pleiades is quite correct you have a dead short on that circuit, you need as stated, examine the loom for damage

i don't get the rac person, after finding a burnt out large fuse, not delving a bit deeper or at least recovering the bike to somewhere a repair could be carried out! as a 30amp fuse blowing points to a serious fault

hi Spen please don't use an ammeter (amp tester) across the battery terminals, a voltmeter is perferable!