Can a Williams dual motor loco be wired for always forward

[HannahsDad]

I have a shelf layouot (17' x 25'), usually pulling 9-11 passenger cars.  Backing up around 72" curves is possible, but slow and I usually just lock my Lionel locos in forward only (especially the post war stuff).  I don't think any of my older Williams locos can do that.  The manual says that after a power loss, you have to wait 7+ seconds, then it will return to forward-neutral-reverse operation.  Any sooner than that, and it will interpret that as a marker to switch to neutral then reverse, etc.

So, is there a wiring way to bypass the electronic e-unit and just run the motors forward only?  Anybody done this?  And if so, anybody have a wiring diagram to share?  My email is [email protected] if someone has a wiring diagram for this.

Thanks!

Scott W.
Allen, TX

[Len]

There are basically two options:

1. Replace the reverse board with the new style that has a direction lock switch:

https://estore.bachmanntrains.com/index.php?main_page=product_info&cPath=77_222&products_id=10587

Instructions: https://www.bachmanntrains.com/home-usa/dwg/dwgs/WilliamsReverseBoardInst(later).pdf

2. Replace the reverse board with a 50V, or higher, full wave rectifier:

Connect the pickup roller to one unmarked terminal, connect the chassis to the other. The motors connect to the +/- terminals whichever way gives you forward travel.

There used to be instructins around on how to modify the original reverse boards to add a direction lock switch, but they have pretty much disappeared. Which is probably a good thing, because the risk of damaging the board while soldering was fairly high.

Len

[HannahsDad]

Thanks for the link.  I didn't know that they had a new board that was a drop in replacement.

[HannahsDad]

In the instructions, it shows a bit of the type of relays that are being used (K1 and K2).  Is it possible to simply either remove the connection to the coil that triggers it?  And if one or both of the motors turn in the wrong direction, to simply reverse the polarity going to the motor?

[Len]

Beats me. I never tried it.

Len

[HannahsDad]

I may just give that a try.  If that doesn't work, I can always replace it with the "new" reversing board.

[671]

Hi Hannahas Dad,

    671 here. Len's use of a bridge rectifier is a cheap and good solution. I used a similar fix for an old Williams SD-45 dual motor unit with a non-functioning motor control board.

Material,Tools and parts needed:

one 6-8 amp 50 volt bridge rectifier ( purchase on line from Jameco Electronics). This will take the place of the motor control board, (only one direction of engine travel, no neutral, always moving when power is applied to the track).

The bridge rectifier ( size of a small sugar cube ) has (4) terminals. Two input and two output. The input terminals can be wired to the engine's center roller pick-up and the other input can be wired to the chassis frame of the loco. When track power is applied to the loco, the bridge rectifier will take alternating track power at the input terminals and (Rectify it) and project a synthetic dc current at the output terminals. This current can be used by the two electric motors within the loco. The motors operate on dc power.

Now: the wiring of the motors:
The two motors run in opposite rotation of each other, clock-wise counter clock-wise. You need to take/cut the wires from the motors at the plugs to the control board. Using the powered up bridge rectifier, determine the correct wiring to allow the motors to power the loco in the correct direction. Use test wires with alligator clips for a temporary hook-up to the rectifier's out-put terminals.

I wired my two motors in "series" ( power from the bridge rectifier dc output into one motor's lead and then the second lead from that same motor to the input lead of the second motor, then the second motor's remaining lead back to the other dc terminal on the rectifier.

Wiring the motors in series reduces the loco's sensitivity to input power fluctuations. It allows you to increase the running voltage to the track without pushing the loco to crazy speeds. The higher track voltage along with the series wired motors allow the loco to "creep" along at a nice constant speed.

This setup will only allow one direction of travel along with no neutral. The loco will always move when the track is powered.

Note: All electrical connections should be shrink wrap or electrical tape. The rectifier can be glued or double sided tape for secure installation.

This fix is quite inexpensive also very satisfying due to the closer to scale type speed of the loco.
Take your time, wire the motors for correct rotation (use test lead wires to determine correct wiring.)

                             Hope this helps ... take your time ... Keep'em Smokin' ... 671