Question with Java assignment, complies but with logic error.

I have an assignment due in a couple of days and just need help with a small step in the code. My code compiles but there is an error that gives me a false output that should give me a true output. Here is the code for the Truck class as well as the code for the TestDriver.

public class Truck extends Vehicle {

	private int towingCap;
	private double loadCap;
	

	/* Default constructor*/
	public Truck(String manufacturer, int cylinders, Person owner, double loadCap, int towingCap) {
		super();
	}
	
	/** 
	 * Constructor with int towingCap, double loadCap args 
	 **/
	public Truck(int towingCap, double loadCap) {
		this.towingCap = 7000;
		this.loadCap = 1000;
	}
	
	/**
	 * Arguments constructor
	 * calling the super class without arguments
	 * double towingCap, double loadCap
	 **/
	public Truck(int towingCap, double loadCap, String manufacturer, int cylinders, Person owner) {
		super();
		this.towingCap = towingCap;
		this.loadCap = loadCap;
	}
   

	
	
	public int getTowingCap() {
		return towingCap;
	}
	
	public void setTowingCap(int towingCap) {
		this.towingCap = towingCap;
	}
	
	public double getLoadCap() {	
		return loadCap;
	}
	
	public void setLoadCap(double loadCap) {
		this.loadCap = loadCap;
	}
  public Truck(){
	  
  }
  
	public Truck(Truck t1) {
	
}

	public boolean equals(Object other) {
		if (this == other)
			return true;
		if (!super.equals(other))
			return false;
		if (!(other instanceof Truck))
			return false;
		Truck otherTruck = (Truck) other;
		if (Double.doubleToLongBits(loadCap) != Double.doubleToLongBits(otherTruck.loadCap))
			return false;
		if (towingCap != otherTruck.towingCap)
			return false;
		return true;
	}
	/* Overriding toString method */
	public String toString() {
		return super.toString() + "\nTowing Capacity: " + towingCap + "\nLoad Capacity: " + loadCap;
	}
} 

Line 42, 83, 155 should all be true, but I can not figure out how. I know I am probably way off. Just need a little help in the right direction.

/** Ch7pr6TestDriver.java
 *  Driver class containing a main method to test various combinations
 *   of Person, Truck and Vehicle constructors and methods.
 *
 *	@author Robert Mann
 * @version 0.2
 */
public class Ch7pr6TestDriver {
   public static void main(String[] args) {
      testPerson();
      testVehicle();
      testTruck();
   }
   
   /** Method to test the Person constructors and methods.
    *  toString() methods should be sufficient to see all Person attributes.
    */
   public static void testPerson() {
      // test empty constructor
      Person p1 = new Person();
      System.out.println("p1: " + p1);

      // test setName() accessor method
      p1.setName("Bob Evans");
      System.out.println("p1's name is: " + p1.getName() );

      // test argument constructor to create "Joe Schmoe"
      Person p2 = new Person("Joe Schmoe");
      System.out.println("p2: " + p2);

      // test copy constructor on an empty Person
      Person empty = null;
      Person p3 = new Person(empty);
      System.out.println("Empty person is: " + p3);

      // test copy constructor to create another "Bob Evans"
      Person p4 = new Person(p1);
      p4.setName(null); // test that empty parameter is ignored
      System.out.println("p4: " + p4);
      
      // test equals methods
      System.out.println("p4 equal to p1: " + p4.equals(p1)); // should be true
      System.out.println("p2 equal to p1: " + p2.equals(p1)); // should be false
    }
    
   /** Method to test the generic Vehicle constructors and methods
    *  toString() methods should be sufficient to see all Vehicle attributes.
    */
   public static void testVehicle() {
      // test empty constructor
      Vehicle v1 = new Vehicle();
      System.out.println("v1: " + v1);

      // test accessor methods on empty Vehicle
      System.out.println(" -- v1's manufacturer is: " + v1.getManufacturer() );
      System.out.println(" -- v1's cylinders: " + v1.getCylinders() );
      System.out.println(" -- v1's owner is: " + v1.getOwner() );

      // populate attributes and test accessor methods on populated Vehicle
      v1.setManufacturer("Ford");
      v1.setCylinders(4);
      v1.setOwner(null); // test that empty parameter is ignored
      v1.setOwner(new Person("Joe Schmoe"));
      System.out.println("v1 is now: " + v1);
      System.out.println(" -- v1's manufacturer is: " + v1.getManufacturer() );
      System.out.println(" -- v1's cylinders: " + v1.getCylinders() );
      System.out.println(" -- v1's owner is: " + v1.getOwner() );

      // test argument constructor to create Marie's Chevy
      Vehicle v2 = new Vehicle("Chevy", 4, new Person("Marie Callendar"));
      System.out.println("v2: " + v2);

      // test copy constructor on an empty Vehicle
      Vehicle empty = null;
      Vehicle v3 = new Vehicle(empty);
      System.out.println("Empty vehicle is: " + v3);

      // test copy constructor to create another one of Joe's Fords
      Vehicle v4 = new Vehicle(v1);      
      System.out.println("v4: " + v4);
      
      // test equals methods
      System.out.println("v4 equal to v1: " + v4.equals(v1)); // should be true
      System.out.println("v2 equal to v1: " + v2.equals(v1)); // should be false
   }
   
   /** Method to test the Truck constructors and methods
    *  toString() methods should be sufficient to see all Truck attributes.
    */   
   public static void testTruck() {
      // test empty constructor
      Truck t1 = new Truck();
      System.out.println("t1: " + t1);

      // populate attributes and test accessor methods on populated Vehicle
      t1.setLoadCap(54.36);
      t1.setTowingCap(10);
      System.out.println("t1's load capacity is: " + t1.getLoadCap() );
      System.out.println("t1's towing capacity is: " + t1.getTowingCap() );

      // test argument constructor to create Betty's Chevy
      Truck t2 = new Truck("Chevy", 4, new Person("Betty Davis"), 34.5, 65);
      System.out.println("t2: " + t2);

      // test copy constructor on an empty Truck
      Truck empty = null;
      Truck t3 = new Truck(empty);
      System.out.println("Empty Truck is: " + t3);

      // test copy constructor to create another Truck
      Truck t4 = new Truck(t1);
      System.out.println("t4: " + t4);
      
      // test the equals method
      System.out.println("t4 equal to t1: " + t4.equals(t1)); // should be true

      // set the owner for this Truck
      t4.setOwner(new Person("Clive Davis"));
      
      // retest the equals() method
      System.out.println("t4 equal to t1: " + t4.equals(t1)); // should be false
      
      // test the equals method on a Vehicle and a Truck
      Vehicle v1 = new Vehicle("Ford", 8, null);
      Truck t5 = new Truck("Ford", 8, null, 75, 150);
      System.out.println("t5 equal to v1: " + t5.equals(v1)); // should be false because
																				  // the "is a" relationship 
																				  // states that a Truck is a 
																				  // Vehicle, but not vice-versa.
   }
}