Think the bug lies in your .equals method.

What should you compare ?

• It seems your .equals method returns true when 2 vectors .components are of different lengthes.

  Are you sure this is the expected behavior ? ( Isn't (1, 2) equals (1, 2) ? )

• In your .add, .subtract & .dot methods you test first if the vectors are equals.

  That means you can't add (or sub, or dot) (1, 2) & (3, 4)...

Hope it helps.

Can you post your solution so I can see about it?