96 6.5 IGN A fuse keeps blowing
 

One day randomly on my 96 gmc 1500 6.5 turbo diesel my IGN A fuse blew on me and kept on blowing more fuses i called heath diesel and told me that my glow plugs and glow plug controller are bad and that the controller is routed to the ign a fuse well i changed my plugs and controller and no difference you can hear the glow plugs warm up and then when you go to crank it over it pops the fuse and all my gauges quit working and only thing that has power are my lights and radio I NEED HELP!