The best ideas, as they say, are the simplest. And never has this been more true than with this bit of lateral thinking from an MRE group member.
I, and most others modellers I know, detest troubleshooting track power problems.
And figuring out which bit of track is causing problems is one of the most tiresome challenges. This is especially the case if your layout is any of a fair size.
Using one of the standard track testers, such a GaugeMaster GM-GM52, is proven but isn’t fun when you have to manually move it around every section of track when you more than a few.
Stuart Peter Hilton, put his thinking hat on and hooked up a Mini Digital Voltmeter display to the axel on a wagon to create a mobile track tester. With a little bit of work, the circuit will fit in both OO and N gauge although you need to consider clearance width for N – 9mm – track.
Stuart’s approach was to use the insulated bogey wheels of an Intercity on one side and then used fine copper wire coiled around the axle and up on each side then attached soldered the wires of the meter to each of the copper wire I will post the link of the meter
Hooking this wagon up to a loco and running it around your layout quickly reveals problems and enables rapid identification of problems. It’s even makes troubleshooting interesting, dare I say fun?
Also, because the read out shows exact voltages, you can identify voltage drops and where your track and wiring can be improved or is heading for a future problem.
Update: The original volt meter referred to in this article is no longer available, an alternative is now given in the link. This is also only applicable to DC / analogue layouts.

Andy is a lifelong modeler, writer, and founder of modelrailwayengineer.com. He has been building model railways, dioramas, and miniatures for over 20 years. His passion for model making and railways began when he was a child, building his first layout at the age of seven.
Andy’s particular passion is making scenery and structures in 4mm scale, which he sells commercially. He is particularly interested in modelling the railways of South West England during the late Victorian/early Edwardian era, although he also enjoys making sci-fi and fantasy figures and dioramas. His website has won several awards, and he is a member of MERG (Model Railway Electronics Group) and the 009 Society.
When not making models, Andy lives in Surrey with his wife and teenage son. Other interests include history, science fiction, photography, and programming. Read more about Andy.
I have a small DC n gauge layout and added one of these inexpensive digital meters, shown in the link in the article, to my control panel to display the voltage coming out of my Morley controller. The meter displays DC only, so to show voltages when the polarity is reversed, I knocked up a bridge rectifier from four spare diodes. The meter doesn’t display anything below 4v (as per the spec), which didn’t really help much for my low speed application but for £2.85 inc delivery, it’s been both useful in comparing the performance of my small fleet and entertaining to install. I’m no expert, but I don’t see how this meter would help with DCC, which I understand uses square wave AC?
Hello
I would öike to build this myself are there more infos of building one
Hi Daniel, it’s really no more than buying the volt meter display to the axle of wagon (make sure you get metal wheels and axle to conduct the electricity). If you’re looking for more info, join the MRE community (free) where the tip came from, I’m sure other members will be happy to help. Andy
Would be interested in buying one if the price was reasonable
would love to see these pre made available
good to see new tips
cheers lawson
🙂 🙂