How to attach wires to the posts of a Lionel train transformer

Last Updated on November 24, 2016 by Dave Farquhar

It took me 20 years to find out I was connecting the wires to my train transformer wrong–and this applies to American Flyer and Marx just as much as to Lionel–and I don’t want the same thing to happen to you. I was making it far, far too difficult to attach wires to the posts of a Lionel train transformer.

Modern transformers have a groove in the post to accept a wire, but vintage transformers don’t. If you’re having problems with the wires coming off your transformer while you try to cinch them down, here’s how to connect to a vintage transformer in three simple steps.

First, assuming you’re using stranded wire, pick up one wire and twist the ends until they form a straight line. Repeat the same process on the other wire. Frayed wire won’t stay in place very well.

Next, take the bare copper end of each wire and bend it into a simple U-shaped loop.

Now the magic happens. Untwist the nut on the end of each transformer post, then place the wire on the post so that the long end of the wire is on the left side and the much shorter end of the loop is on the right. If you want, you can even pinch the loop closed with a pair of needlenose pliers, but that isn’t completely necessary. Now when you tighten the nut, the wire will naturally want to stay on the nut, rather than falling off. Attach the other end to the clip on the lockon.

On most Lionel transformers, post A goes to clip 1 on the lockon, and post U goes to clip 2. A1 and U2. Steak sauce and rock band. Or, depending on your age, steak sauce and spy plane. You can confirm your particular transformer here.