Sorry for using your thread Assassinator :-\
DeadMeat just sent me a working cpp file for you to try swift88
Change the necessary lines as:
class M113Ambul: M113
model=M113_ambulance;
HERE IT GOES:
class AllVehicles: All {};
   class Land: AllVehicles {};
   class LandVehicle: Land {};
   class Tank: LandVehicle {};
   class APC: Tank {};
   class M113: APC {};
   class M113Ambul: M113
   {
      //--
      accuracy=1000; // never recognized
      vehicleClass="Support";
      icon="Ambulance_move";
      picture=im113_ambu;
      nameSound="ambulance";
      scope=public;
      displayName=$STR_DN_M113_AMB;
DefaultWestMagazines(0);
      attendant = true;
      model=M113_ambulance;
      weapons[]={};
      magazines[]={};
      hasGunner = false;
      transportSoldier = 3;
      type=VArmor;
      //threat[] VSoft, VArmor, VAir
      threat[]={0.0, 0.0, 0.0};
      typicalCargo[]={};
cargoAction[] ={ManActM113Medic,ManActM113Medic, ManActM113Injured};
      cargoIsCoDriver[] = {false, false, false};
      transportMaxMagazines = 0;
      transportMaxWeapons = 0;
   };