There have been questions and answers on this subject on an almost daily basis. Maybe you should take the trouble of SEARCHING for and answer instead of ASKING.

As for your question: don't use a circuit as you describe. Although the information provided in your posting does not fully justify the answer (I don't know what stepper motor you use), it's safe to say that you are likely to get problems.

As for the heater thing: think of Ohm's law. A heater is nothing but a bad cable (high resistance) that converts potential energy into heat. The purpose of a connection cable (extension cable) is to get the electrical energy INTO an electrical apparatus, not to waste it into heat BEFORE it reaches the device. So, unless you want your energy spilled BEFORE it reaches your motor (which is where you want it to go), don't convert it into heat by adding resistors.