Fire gutted a 2001 Peterbuilt tractor truck Friday morning in Brownwood.  The Brownwood Fire Department responded to County Road 234, just south of the entrance to Vulcan, on the city’s west side.  According to Fire Marshal Buddy Preston, the truck had been brought to a shop for repairs and that he feels reasonably sure that an electrical short in the engine compartment may have caused the fire.  A nearby house and shop were not damaged.  Brownwood Police were first on scene followed by two engines from the Fire Department.  The call came in prior to 8:00 am Friday.