I have isolated my key off battery drain to the rear wiring. If I disconnect the major connection bus near the parking brake pedal ( the one that has the bolt in it) the draw stops. The draw is about 3 amps. It is winter here in Ontario Canada - no snow yet but it is getting cold. Since I do not have a warm place to work, any major detective work will have to wait until the warm weather. Right now I disconnect the battery after each outing if the truck will be sitting for a few days. What could be the possible source of the draw. Looking for some suggestions to start the investigation when the sun shines.