Last night my 20A fuze blew for my Auxiliary Circuts i was gonna temporarily put a 25A in to go to my nearest store and get a 20A but it drew sparks and blew that fuze instantly what do it do what may be wrong

its somewhere in my cigaret lighter ports cause my main port doesn't have any power where would i even start

(1988 XJ40)

 

Auxilliary would be items added by the owner like alarm system or extra horns? Look for what isn't working and check its wiring. Sounds like a hot wire came loose and landed on a ground area.....