This installation is for a HO Scale Walthers Trainline GP9 using a TCS WOW121-Diesel Decoder, AK-MB1 Motherboard with built in Keep Alive®,
motor mount and UNIV-SH4-C WOWSpeaker kit.

This was performed by our friends from DCC Xpress installations.
They offer high quality WOWSound installations for a flat rate complete with free return shipping!
You can find them at:

These items are available in the WDK-ATL-2 which was used for this installation.
AK-MB1 Motherboard with Keep Alive™ WOW121-Diesel Decoder UNIV-SH4-C Speaker Kit
Click here for more information on the WDK-ATL-2 and the rest of the WOWDiesel Kits line.

Important Soldering Tip:
Please do not use any flux either liquid or paste on the mother board. It will damage it. Use only Rosin core solder approved for electronics use.
We recommend to use only Kester "44" rosin core, SN63PB37, .015" diameter, part number 24-6337-0007.
This can be ordered from Techni-Tool under Techni-Tool part number 488SO157

HO-Scale Walthers Trainline GP9 shown prior to installation.


    To start off this install, we must first remove the front and rear coupler screws highlighted above and their housings.

With the couplers removed, while gently pulling outwards at each end and along each side of the frame, lift the shell off of the frame.
Take care to release the handrails as you lift off the shell so they don't break.

The Walthers Trainline GP9 shown with the shell off. Remove the wires from the original lighting board and remove it from the chassis.
To allow a space for the motherboard and speaker, the frame weight must be removed.

With the weight removed, trim tin or lengthen the wires as necessary and using small lengths of TCS 3/32" and 3/64" shrink tubing, insulate these solder leads.
Using double sided foam tape, secure the motor mount to the top of the motor.

Attach the AK-MB1 to the motor mount with the same double sided foam tape and solder the motor and track pickup wires according to the included wiring diagram.
In this installation to facilitate adequate room for the assembly, the motherboard is mounted backwards and offset as shown.


Using a small dab of hot melt glue, secure the front and rear LEDs to their light tubes.

We have found that LED light output is brightest when shinning directly into the end of the light tube, but in some circumstances they may be placed along the length
of the tube as well with satisfactory results. In doing so, white light LED output would be least affected, while non white LED output will be more affected by placement.

Solder the wire lighting leads to the motherboard according to the included wiring diagram. This particular installation also has ditch lights added in to pad #1.

TCS motherboards include on board current limit resistors for LED use. There is no need to apply external resistors for LED use. 

With the 25mm X 14mm WOWSound speaker inserted into the UNI-SH4-C enclosure, mount this assembly to the frame as shown and solder these wire leads
to the motherboard according to the included wiring diagram.

If your speaker enclosure installation covers the portholes on the enclosure, we recommend adding new port hole(s) similar to the original porting. Be sure that the new portholes are the same size and amount of the original and are vented freely into the locomotive We have found introducing a port of the correct size greatly increases the volume and sound quality of the installation. Too much or too little porting decreases the sound quality.

You can now plug in your WOW121 decoder.

Lastly, in order to keep the wires neat and prevent possible shorts, lace the wires into a bundle using lacing cord, which is a wax impregnated string 
used for wire bundling and making harnesses. There are many choices of lacing cord available from Digikey
We use part number 802534B BK032-ND

Now you can close up the locomotive and reinstall the coupler assemblies. Be sure to be mindful of wire routing and reassembly of the shell as to not damage 
or foul the installation. Your Walthers Trainline GP9 is now WOWSound equipped and ready to roll!

Other solder tips: When stripping wire, only strip a tiny little bit of the insulation. Strip no more then a 1/64 of an inch. When the wire gets tinned with solder the insulation will shrink back more. Try to not expose any more wire then half the length of the solder pad at most. In no case should solder or exposed wire wire ever be outside the boundary of the the solder pad you are attaching a wire to.
Click here for important information on properly Stripping and Tinning wire

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