Hopefully this is the right place to post this. I recently acquired a 1681E very cheap, because it didn't run. Is there a way to wire the motor direct, without the E unit connected, to make sure the motor is functional. The E unit looks to be in good shape, but I would like to test the motor, by itself, to eliminate where the trouble lies, whether the motor or E unit. Any help would be appreciated.
It is very easy to run a lionel motor without an E-unit. Power from the center rail runs to either brush and from the other brush to the field (stationary) coil. The other end of the field coil is always grounded through the frame and wheels to the outside rails.
Motor doesn't run in the forward direction simply reverse the brush connections. This is all the e-unit does.
While we're on the subject of bypassing E-units I thought I might talk about Marx motors.
Lionel and Marx Post War motors are fundamentally the same. They are called series wound motors and run on either AC or DC. The rotor winding (Rotating assembly) is in series with the field winding hence the name.
The main difference between Marx and Lionel is that Marx grounds the rotor windings through one brush (permanent connection to frame and outer rails) while Lionel grounds the field winding. Reversal is accomplished the same way on each motor by changing the relationship of the two windings, rotor and field. by the E-units. Marx of course only has forward and reverse positions on its E-unit (Marx simply calls their unit a reversing unit) and Lionel has the slightly more sophisticated three position E-unit which includes a neutral position.
I bought a Lionel 1668 on eBay at a good price. The listing said it would not run, but the light worked and the motor hummed. When I got the engine, it checked out to have a short in the e unit. I disconnected the e unit and connected the wires as follows.
One brush should be connected to one end of the field winding. The other brush should be connected to the pickup. The other end of the field winding should be connected to the locomotive frame.
This engine runs great, it is fast and pulls 4 passenger cars and a baggage car. The only draw back is it only runs forward. But who cares.