I have a Quartz battery operated Westminster-Whittington Burlwood Curio Wall Clock Model # 3178 from JC Penney's. I have had it for over six years and this time when I changed the battery and put the pendulum back on it's holder it won't swing. I have tried to give it a gentle swing to get it going and it dies down to a stop in a short time. the pendulum holder swings back and forth okay without the pendulum in it. I think the pendulum is for looks only as the clock keeps perfect time whether the pendulum is on the holder and swings or not.
Your pendulum is moved by a magnetic field. Make sure it is hanging close enough to the electric magnet. Try putting a newer battery in it just in case the one you put in was not strong enough. Also some of these movements use a separate battery for the pendulum.