Re: Stewart

Posted by HH56 On 2022/12/28 23:25:58

You might also check with Ross or Pacific Southwest to see if either have motors. A different motor might cost less than having one rewound.

That burned field coil issue happens all too often when people do not know that Packard used motors with two oppositely wound but separate field coils for reversing. The usual assumption is that like most other motors you need to connect the two wires to power at the same time. NOT SO with this type motor.

Anyone new to Packards who reads this just be advised that with a couple of exceptions almost all postwar Packard reversible motors -- antenna, windows, seats, TL compensator -- need the case grounded. Only one wire at a time will then connect to power to make the motor run in one direction. To reverse direction, disconnect the first wire and connect the other wire to power. Connecting both wires to power is a big mistake because if case is not grounded, power cannot go thru the armature so motor cannot turn and field coils only will burn or if it is grounded, with both field coils and armature energized the magnetic fields cancel each other and motor also cannot turn. Either way, the motor is just sitting and field coils are getting hot and if case is grounded, armature is also getting hot.

The exceptions to that type motor that I can recall at the moment are the few motors having 4 wires out. Those need special relays or switches to change the field to armature magnetic relationship when changing direction. Case is not grounded on those because ground is provided by one of the wires. Switch or relay takes care of connecting the armature to the field coil in the desired orientation and providing power or ground to the remaining wires. Motors like that are the prewar Deluxe heaters, the prewar hydraulic window pump motor, the 54 4 way power seat, and the 56 pushbutton shift motor.