Connectors For Use With HO Locomotives

One major area of difficulty for the model train modeler is miniature connectors for HO, HOn3 and Sn3 scale steam locomotives.

There is a manufacturer, called Miniatronics Corp., that produces cables with male and female connectors for the use of the aforementioned scale steam locomotives. The problem is that the backshell is to stiff and long. I’ve tried using them on large steam engines but the combination of the backshell and wire harness lifts or flips the tender off the track. This is especially true when the engine is in a curve or going through a switch/turnout.

There are other connectors but they are too large for these three scales. The exception is Soundtraxx who produce single conductor sets (male & female) for this particular usage. The problem with this type of connector is the modeler ends up with several single connectors dangling between the tender and engine. Generally you need five wires with connectors between the tender and engine.

The only companies that carry the type of connectors needed for these scales are Bachmann, Athearn and Walthers Heritage series. The problem the modeler faces is that these companies will not sell the connector sets to a customer unless it is for a replacement for a damaged set on one of their locomotives.

I’ve tried Bachmann and Athearn personally with negative results. Walthers did not have any of their connectors in stock. Walthers, who seem to want to sell anything that pertains to model railroading, may sell the connector sets they produce for their Heritage series. This issue I will have to pursue further and will report on my success or failure in the near future.

The requirement is to have different connector sets that can be accommodated between the steam engine and it’s tender. The needs are as follows:

1. Two conductor male and female connectors.
2. Three conductor male and female connectors.
3. Four conductor male and female connectors.
4. Five conductor male and female connectors.
5. Six conductor male and female connectors.

The connector set requirements maybe, for example, the following combinations.

1. The use of the two conductor connector set would be for the wires leading to the light in the steam engine. The three conductor connector set would be for the three wires required to run the motor. The two conductor set would be blue and white wires and the three conductor set would be red,waterproof Butt Connector  orange and gray wires. The red wire is the conductor for the engine that takes the place of the drawbar. This is similar to the Bachmann wire harnesses and connectors. The problem with the Bachmann system is they do not color code their wires per NMRA standards. In fact none of the three companies mentioned follow NMRA color coding standards. When you are trouble shooting a problem this can be the pits.

2. The use of the five conductor connector set would be for all light and motor wires. Using this method has to do with the ability to place the correct hole or holes in the tender for the female connector.

3. The use of the six conductor connector set is for those modelers who wish to install the brown wire for the steam engines cam. This is unique for sound systems so that you can get the steam cadence as accurate as possible as the cam rotates during operation.

4. The four conductor connector set is not used very often unless there is a particular set of conditions where four wires are needed.

A great use of the single conductor connector set is for those that are running DC operations. A big problem with brass steam locomotives is the drawbar. This connection has a tendency to short out or create an electrical fault. It is a very good idea to run a red wire soldered to the frame of the engine to a black wire that is soldered to the frame of the tender. With the connector set between the two wires you now have a very good connection between the engine and tender. This eliminates the use of the drawbar acting like an electrical wire.

My over all point is make the modeler aware that there are no known sources for the type of connectors that I have discussed in this article. If you had to buy these connector sets from China, Korea or Japan you would have to pay a large premium or have to buy 1k to 10k of these connector sets plus import duties.

I am still researching various manufacturers in the U.S. that may produce these supper mini-connectors. I will write an article if I can find a source.