Athearn GP7 Decoder Installation featuring the GEN-MB1 Motherboard with Keep-Alive™, WOW121-Diesel Decoder, and GEN-SH2 WOWSpeaker Kit by TCS

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
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-ATH-6 which was used for this installation.
GEN-MB1 Motherboard with Keep Alive™ WOW121-Diesel Decoder GEN-SH2 Speaker Kit
Click here for more information on the GEN-SH2 and the rest of the WOWDiesel Kits line.


First, remove the coupler box screws and the coupler boxes from both ends of the locomotive.

With the couplers removed the shell should lift right off the chassis.

Remove the original lighting board from the chassis and remove the wires from the board tabs.

Next, we will prepare the speaker location. Remove the screws holding the rear weight on the frame.

Next, remove the plastic wire guide beneath the rear weight.

Slide the GEN-SH2 speaker housing over the 2x screw posts that originally held the rear weight.

Route the track and speaker wires through the two holes at the front of the enclosure, slide the 35mm x 16mm speaker into the housing, and screw the speaker and housing in place using the original weight screws.

Next, mount the GEN-MB1 on the motor just like the original lighting board and begin wiring it up according to the wiring diagram in your motherboard manual.

Solder in the lighting connections from the shell and install the WOW121-Decoder to complete the wiring of your installation. This mother board has a 1.5volt power supply to power all the original 1.5v bulbs that come with the Athearn locomotive. It can be configured for LED operation as well, the mother board has built in current limit resistors for LED use. Consult the wiring diagram for LED use.

All the original 1.5volt bulbs supplied with the Athearn loco were used. The "FL" solder pad is the forward 1.5v solder pad for the front lights. The "RL" solder pad is the reverse 1.5v solder pad for the reverse lights. The solder pad marked "1.5V" is the common power source for the bulbs.

Finally, you can replace the shell (it should slide over the installation easily), and reattach the couplers on the shell.

Your WOWSound equipped engine is now ready to run!

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

Like us on Facebook Subscribe to our YouTube Channel Join our newsletter
  Back To Top
Entire contents © Copyright Train Control Systems 2004-2018