1991 ford f150 4.9 liter 2wd manual transmission

Hi ok here’s my issue I drive a 1991 ford f 150 4.9 liter with manual trans I had it in the shop about a week ago they had the starter solonoid changed and they said they had to fix fuseable links with in my main wiring harnass well it started drove one day and when I started it again my starter wouldn’t disengage I turn the truck off but the starter wouldnt stop running I had to pop my clutch to stop it then my neg wire on my bat melted so I send it back they replace the starter solonoid again will then my starter stop working so I replaced that it started drive for a hour or so came out to start it back up it did it again this time pos wire on bat melted new starter smoking now what could be the problem I even replaced the ignition switch too