# engine direction



## alvin (Feb 6, 2013)

Hi all

I have a used locomotive that seems to be a athearn
the problem is that it goes backward when all my other engine go forward.
Changing the polarity on the motor does nothing.
My understanding is that the trucks pick up the current on the wrong side of the track, how could it be. :dunno:
Your help is always greatly appreciate.

By the way thank you all for the info about my tortoise on another thread now everything works. :thumbsup::thumbsup:


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## alvin (Feb 6, 2013)

Forgot to tell you it is ho and dc


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## Brakeman Jake (Mar 8, 2009)

Even if the trucks have been swapped in the past,swapping the wires to the motor should correct the direction problem.Why it doesn't seems impossible to me.

I'd try disconnecting the wires to the motor and power it directly (both ways) with a nine volts battery to see what happens.


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## MtRR75 (Nov 27, 2013)

alvin said:


> Changing the polarity on the motor does nothing.


How did you change the polarity of the motor?


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## DonR (Oct 18, 2012)

You usually find a red wire from the right hand wheels to
the motor and a black wire from the left hand wheels to
the motor. If that is not your case what do you find?

A DC motor goes forward when right hand track is positive,
backward when it's negative if wired as above.

Don


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## alvin (Feb 6, 2013)

there is no wire to the motor,
bottom of the motor connect directly to the frame via a copper clip
top of the motor have the same copper clip which connect to the trucks via a piece of metal folded to go over the flywheel.


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## DonR (Oct 18, 2012)

Alvin

I have a Bachmann locomotive that uses a similar NO WIRE system for
power transmission. Very clever design and it works well.

My best guess as to what is causing your reverse motor operation is that
someone took it apart and reinstalled the motor so that the
tabs were touching the wrong contacts. The only way
to correct that is to again take it apart and flip the tabs.

Don


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## alvin (Feb 6, 2013)

Don

Since i am not familiar whit some thermes in RR what is the tabs you are taking about.


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## traction fan (Oct 5, 2014)

*Reversal*



alvin said:


> there is no wire to the motor,
> bottom of the motor connect directly to the frame via a copper clip
> top of the motor have the same copper clip which connect to the trucks via a piece of metal folded to go over the flywheel.


alvin;

Have you tried taking the motor out and turning it upside down to re-mount it? That would have the opposite motor poles connected to the loco frame, and the metal strap. This should make the engine run in the same direction as your other locos.

regards;

Traction fan


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## MtRR75 (Nov 27, 2013)

Since you are running this loco on a DC system, unless you are trying to run multiple locos off of one transformer, this loco will have it's own, dedicated transformer when it is on the layout. You can simply use the reverse the direction switch on the transformer to reverse this loco's direction. Then flip it back when you swap out that loco for another.

Much simpler than operating on the loco.


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## Mr.Buchholz (Dec 30, 2011)

Brakeman Jake said:


> Even if the trucks have been swapped in the past,swapping the wires to the motor should correct the direction problem.Why it doesn't seems impossible to me.


Could both trucks be reversed and the wires at the same time? I had an older loco either only go backwards or not move at all until I moved everything around. The only other thing I can think of is a weak soldering link on the motor wires. You never know.

-J.


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## santafewillie (Feb 13, 2016)

You never answered MtRR75's question regarding changing the polarity of the motor. Old Athearns have no wires. It sounds like either the trucks were removed and reversed when re-assembled, or the motor was re-installed upside down. When you take the shell off, the tabs from the trucks that come up and make contact with the metal strip should be on the engineer's side. If not, then swap the trucks front to back to correct the problem. If they are already correctly oriented, then the motor is upside down. That can be corrected by removing it and re-installing it correctly or by swapping the trucks to the opposite orientation, whichever is easier for you.
Good Luck.
Willie


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## alvin (Feb 6, 2013)

Thank you all again,
Regarding changing polarity I just use some jumpers directly to the straps on the engine.
Swapping the trucks did solve the problem. 
You are a bunch of nice guys, I have been reading this forum for quite some time now and found a lot of information that greatly helped me on my layout.
Keep on guys.

Alvin


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## Mr.Buchholz (Dec 30, 2011)

alvin said:


> You are a bunch of nice guys, I have been reading this forum for quite some time now and found a lot of information that greatly helped me on my layout.
> Keep on guys.
> 
> Alvin


:smilie_daumenpos: 

And you as well!

-J.


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