Testing electric train track

Last Updated on December 13, 2021 by Dave Farquhar

I have a method of testing electric train track from Lionel, American Flyer, Marx or any other brand. The key is to test it one piece at a time, so you know any problem you found is isolated to a single piece of track.

Here are a couple of different ways to test, depending on what tools you have available.

What you need

• Track (of course)
• A transformer, lockon, and two pieces of wire OR
• A digital multimeter

Testing a loop of track

I recommend testing one piece of track at a time, but if you have a loop assembled and it’s giving you trouble, divide and conquer. Split the loop of track in half, then test each half. Find the bad half, then divide that bad half in half and test both. This lets you quickly narrow down the problem piece or pieces without completely disassembling everything.

Just split up the track and follow one of the two testing procedures below.

Testing with a transformer

The crudest way to test is to connect a lockon to a single piece of track, then wire it up to your transformer and turn on the transformer. If the transformer clicks or the short-circuit light comes on, then you know that piece of track is bad. The problem with this test is that it can sometimes take a little time for the circuit breaker to trip, so you might think a piece is OK when it isn’t.

A slightly better test is to put a locomotive on the track and see if it shows any signs of life. If there’s a short in the track, the locomotive won’t get any power and will appear to be dead.

Testing and troubleshooting track with a multimeter

But by far the safest and best way to test a piece of track is to use a multimeter. It doesn’t have to be an especially fancy or expensive one. Turn the multimeter on to continuity tester or ohmmeter mode. When you first turn the multimeter on and hold the leads in the air, you’ll have no continuity and infinite resistance. My multimeter displays “1” in that scenario. That’s the reading you want to get between the rails of your track.

2-rail track

With two-rail track, put one lead on each rail. You should see infinite resistance, or no continuity. If you see continuity, the track has a short in it and you need to replace the insulators. Don’t worry, you’ll probably find everything you need for the repair in your trash can. No, I’m not kidding.

3-rail track

With three-rail track, put one lead on the center rail and the other lead on one of the outer rails. You should see infinite resistance or no continuity. Next, move the lead from the outer rail over to the other outer rail. Again, you should see infinite resistance or no continuity. If you see continuity, the track has a short in it and you need to replace the insulators.

Note that on three-rail track, it’s normal for the outer two rails to be connected electrically, so there’s no need to test the outer rails for continuity.

Methodology

Test one piece at a time, then put the good track in one pile and the bad track in another pile. Continue until you have enough track for your layout, with enough spare pieces to make you comfortable. When you finish, be sure to change your multimeter back to AC or DC voltage, to avoid damaging it the next time you use it. If I’ve made you curious and you want to know why, you might want to check out my earlier entry Fun with Multimeters.

For more information

If you have damaged track, it’s usually possible to fix it.

I find that adding ties to the track really improves its looks on the layout. It makes it look less unfinished. Here’s how to make wooden ties, or for a closer-to-factory look, how to salvage ties from damaged track.

And here’s advice on how many lockons you need.

Finally, here’s some advice on getting your train and transformer ready to go.