When we use a pendulum to ask a question, it is important to set a clear intention about whom are we asking the question from? Are we asking a question of the pendulum, our self, Higher Self, Angel or an Ascended Master? If the focus and direction of a question is not clear, our ego and lower desire can simply take over and answer you back through the movement of the pendulum. So, it is important to set a proper focus and intention, so that we know exactly who we are working with.
Asking a question of the pendulum will not give you an answer. This is simply because the pendulum is just a tool, not the source of wisdom.