Your moral compass is something that is deeply developed over time, upbringing, life experience and autonomy. For teens, morality is heavily influenced by parents until those life experiences and belief systems are developed. Since you play such a large role in developing your teen's moral compass, you'll need to be careful about how you present your standards and rules for living. Your teen is watching you -- even if you don't realize it -- and forming his future opinions on morality and standards every day.
As a parent, you're the largest influence on your teen's moral compass, since you're in charge of setting rules and standards for your family. By having ground rules in place for issues such as dealing with other people, honesty, academics and setting goals, your teen naturally has the beginnings of a personal moral compass already in place. Of course, you also need to model those behaviors to help them become important to your teen. For instance, the U.S. Department of Health and Human Services notes that a teen who sees substance abuse as morally wrong, rather than an autonomous choice, are less likely to use themselves. Modeling what you believe to be right and wrong helps your teen follow suit.
Talking to your teen is another way that you can first gauge where his moral compass points to and second, help him develop his compass. While your teen might be a one-word answer aficionado, you can get him talking by answering the right questions, like, "What would you do if your friend wanted to copy your test?" or "Do you ever feel like your friends get to do stuff you can't?" These conversation starters can help your teen think about certain situations and how his own moral compass would dictate his reactions.
While it may seem like you're constantly at war with your teen, it's important that you step back and see the core values at work when you're in an argument. Your teen's moral compass can sometimes be skewed by her core values. For instance, perhaps she allowed her friend to cheat from her test because being a good friend is important to her. Maybe she lied about her grade at school because she doesn't want to disappoint you. While your teen won't always make the decisions you would -- or want her to make -- there's a good chance that her core values are coming into play and also affecting her decisions.
While your teen is still technically a minor, he's experiencing the first tastes of adulthood through more freedom, more complicated social experiences and responsibility. His moral compass may not be exactly the same as yours. You can teach him your standards, model those values and make them important in your home, but your teen has the autonomy to create his own moral compass. Respect that individuality -- as long as his compass is still on track to him becoming a responsible, happy and functioning adult, it's OK if his morals are slightly different than your own.