Fusable link questions

thanks for the help /6dan and 67dart273 . i think i traced my problem back to the amp meter/guage behind the dash. my car 73 duster has this box with three prong and cylinder with 1wire that plugs into back of dash/circuit panel. can i bypass this or replace it i looked at some other post but did not see my type,style . sorry about the spelling discriptions ect i am starting to loose my mind