Athearn GP7 Decoder Installation featuring the GEN-MB1 Motherboard with Keep Alive®, WOW121-Diesel Decoder, and GEN-SH2 WOWSpeaker Kit by TCS.
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!
Important Soldering Tip
Please do not use any flux either liquid or paste on the mother board. Over time, the acidic properties of liquid or paste flux will begin eating away at the fiberglass PCB and will damage it. Use only Rosin-core solder or no-clean flux approved for electronics use.
TCS recommends the use of Kester "44" Sn63 Pb37, .015" diameter Rosin-core solder. Kester part number 24-6337-0007.
You can order this solder from the following retailers:
Digikey - PN:KE1110-ND
Techni-Tool - PN:488SO6775
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