where to buy PCM,Ford?

reasson I ask is that I have had problems with the battery going dead wit hthe car just sitting. I narrowed it down to a circuit that is for the Instrument cluster/PCM. It is to cold out to mess with it anymore tonight. I will unplug the computer in the morning and see if the draw goes away. If so, the PCM is what has the problem. Maybe it will be something else.