Lionel 623 Switcher e-unit problem

I ran into one e-unit which had one of the coil wires shorted to ground (the one that goes to the switch lug. I shifted the wire a bit and re-insulated the wire to resolve the problem

C.W. Burfle,

The coil wire (to the switch lug) does not appear to touching anything. However, I noticed that when I power up the engine,  small sparks are present where the switch lug coil wire goes into the top of the coil, which then shorts out the engine. Could the wire be broken under the top of the e-unit. See attached photo.

Yes, the short could be under the top bracket. Maybe you can slip a piece of paper or index card in there to act as an insulator.
Otherwise, the e-unit can be disassembled to insulate the wire.
That cover is staked on in four places at the bottom. A screwdriver can be used to carefully pry the cover free. Just be careful, and don't use too much force. Don't want to bend parts any more than necessary.

You would need to disconnect the wires and remove the e-unit from the loco.

Upon further investigation, the wire is broken under the top of the e-unit. When I take the e-unit apart as you suggest, can this small, broken coil wire be repaired?

Here is a picture of the top wire. You will have about 1/8 " that will need to be stripped and a new wire soldered. Upon reassembly a piece of electrical tape will insulate the solder connection from the frame. The second picture show the tabs are slightly filed to help removing the frame. A drop of CA adhesive upon reassembly will lock the frames together.

Thanks, I will get working on it and keep you informed on my progress.

After slightly filing the tabs, I was able to carefully remove the frame from the e-unit. The wire on the top of the coil was broken. The cellophane tape, which apparently was there to insulate the top coil wire from the frame, was brittle and loose.  This worn tape allowed a short between the coil and frame and an eventual failure of the top coil wire.

I was able to solder a new, small wire to the remnants of the top coil wire and covered the solder connection with a shrink tube and electrical tape to insulate the connection from the frame. After soldering the other end of the new, small wire to the appropriate lug on the e-unit, the frame was easily snapped back into place on the e-unit. All of the e-unit wires were then re-soldered onto the engine.

The e-unit now functions as designed and my 623 Switcher runs beautifully. Many thanks to C.W. Burfle and Stew1957 for lending their expertise, which allowed me to repair my Switcher!!!

Glad you got it working those early switchers 622,6220,623 624 are Lionel's finest made switchers in my opinion and very smooth runners.