# Rails polarity



## rva1945 (Feb 11, 2016)

I have this decoder, a Bachmann E-Z Command no. 44915.

The pins layout is well explained, and it mentions that pin 4 (black wire) goes to left rail pickup, pin 8 (red wire) to right rail pickup.

Now, left or right with respect to what? How do I tell? Will I fry the decoder if I connect those pins the other way?


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## leadsled (Dec 25, 2014)

I would think the loco would run the opposite way you select on your controller if they are hooked up backwards.

I would not believe it would fry the decoder...


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## alaska railroad (Oct 20, 2015)

If I understand you correctly, you are asking what side of the loco is left and what side is right.

The right side is the engineer side, or in other words if you are looking forward from the rear of the loco , the right side of the loco is the right. So you're red + wire would go to that pick up.

The left side obviously,would be the opposite. Hope that explains your question.


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## redman88 (Nov 25, 2015)

If you get it back words you just set the correct cv to make it change direction. No harm no foul


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## Cycleops (Dec 6, 2014)

This one is easy to remember, R for red and right so black is left. Some loco manufactures don't follow this code. Grey and orange for the motor, if you get these wrong ( it will run backwards when forward is selected) just swap them over.


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## mopac (Feb 24, 2011)

You got good advice here. I agree with every post. They are all correct.
Doesn't always happen. Good luck. You will be fine. Git r done !!!


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## DonR (Oct 18, 2012)

I'm with the red right rail advice, but you also must
be certain to identify which motor tab was connected
to that red wire. Your decoder manual will tell you
which color wire to connect to that tab. As was
mentioned, these two factors control the direction
of loco travel.

And be sure to test with a mutimeter set to ohms
probe for any connection between the motor casing and
any other part of the loco.

Don


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## redman88 (Nov 25, 2015)

When I converted my most recent engine I got lucky when I soldered my wires. Didn't mark the engine when I pulled it out.


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## Odyknuck (Dec 31, 2015)

DonR said:


> I'm with the red right rail advice, but you also must
> be certain to identify which motor tab was connected
> to that red wire. Your decoder manual will tell you
> which color wire to connect to that tab. As was
> ...


Curious , if the brush wires are disconnected from motor why would you need to be concerned with the motor case?

Sent from my SM-G920V using Tapatalk


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## DonR (Oct 18, 2012)

It's only a test to make certain that some internal or
external motor part is contacting the frame. Should this
happen you would damage your decoder. It should
be done before you apply first track power to the
decoder.

Another test for protection of the decoder is from each
motor tab to frame. There should be no reading on ohm setting.

Don


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