This installation is for a HO-Scale Intermountain SD40-2W using a TCS WOW121-Diesel decoder, IB-MB2 with Keep-Alive™
and IB-SH1 WOWSPeaker by TCS.

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-INT-1 which was used for this installation.
IB-MB2 Motherboard with Keep Alive™ WOW121-Diesel Decoder JST Speaker Harness INT-SH1 Speaker Kit
Click here for more information on the WDK-INT-1 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 Intermountain SD40-2W prior to installation.


In order to remove the shell, we must first remove the front and rear couplers screws highlighted in red above, the couplers and their housings.

With the couplers and their housings removed, the shell can be lifted up and off of the locomotives chassis. Above is a view of the shell removed.

Cut and remove the zip-ties that hold the wires in place and identify the wiring layout. Be very carefully not to damage wires when removing the ties.
Remove the four screws as highlighted above in red, saving them for later.

Remove the original lighting board and being careful to preserve the plugs, unplug the connectors.

Utilizing the original screws, attach the IB-MB2 motherboard to the chassis, then plug in the original connectors onto the motherboard in
the appropriate locations according to the included wiring diagram. Unscrew and hold onto the screw highlighted above in red on either side of the speaker enclosure. We will not be reusing the original speaker or enclosure, but we will be re-using the screws.

Shown with the speaker removed.

With the 35mm x 16mm speaker inserted into the IB-SH1 enclosure, using the two original screws, attach this assembly to the frame.

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.

Plug in the WOW121 diesel decoder. Reattach the shell taking care not to foul any wired during installation. Your Intermountain SD40-2W
is now WOWSound equipped and ready to roll!

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

Finally, place the locomotives shell back on and reinstall the front and rear couplers and their housings. With this installation, you can independently control the front and rear headlights and marker number board lights.

Your HO-Scale Intermountain SD40-2W 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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