late 1688 e unit wiring

[Johnny no Cash]

I have a late (2) 2-1/8 thru screws holding motor to shell mod 1688-e. Someone has re-wired it at some point, and I need to know where the wires from the 2-and4-. finger contacts go should this hook up like a 2037? or are prewar's different? Right now, it has one direction only, and only 1 wire is connected to a brush holder and it comes off the left contact of the 4 finger unit. The 2 finger unit has 1 wire to the motor field, and there is a second wire on the other end of the motor field windings that isn"t connected to anything. The old drum was in 3 pieces, a victim of stg in a too-hot attic, maybe. I put in a new drum, which cycles properly, but still only goes in 1 direction, can't get motor to reverse. Any help with wiring attaching points would be appreciated,thanks

[TrainLarry]

Here is a page from the service manual for the 1688. It has the wiring diagram for the e-unit and motor.

1688 wiring diagram

 

Larry

 

[ADCX Rob]

[Johnny no Cash]

thanks for the wiring diag. that will help

[Johnny no Cash]

thanks, rob, I should be able to correct the problem now

[teledoc]

Rob shows the correct diagram for the version of motor you have.  That motor is identical to the Postwar 1654 with the single reduction gear.  The 1688/1688E locos used three different motors throughout their production.  The first one is the Lionel JR. motor, for 1936 only, which was retagged as Lionel 027 for 1937 onward.  The second motor used one single 2 1/8" screw near the rear of the body, to attach the motor, which is about 1938 vintage, and the last motor is the one you have with the double screw through the body.  Make sure of one thing with the brush plate, that the right hand screw makes a good ground against the washer, otherwise the loco won't run.  That screw is the ground path for the opposite brush.

I personally own all three version motors, and I have 13 different body variations, with all different features to the bodies, discounting the nameplate or color variations.  Some variations are listed as 1688 others 1688E, and the colors are either Gunmetal gray or Black, which would bring the total of variations to 18 separate variations.

If you can't understand the diagram, the bottom two finger contact of E unit goes to one field coil contact.  The center of the 4 finger contact connects to the opposite field wire contact.  The far left goes to the left side brush, and the last contact is your collector pickup lead.