HO-Scale Athearn Genesis SD70MAC using the TCS T4X decoder and blinking ditch lights, performed by J.M.
First remove the coupler screws and slip the couplers out of the shell as shown in the image below. (NOTE: there are couplers at both the front and rear of the locomotive.)
Next, gently lift off the shell
After removing the dummy plug from the wired 9-Pin JST connector you should see a circuit board that looks like the image below.
Once you have two sets (each one powering one bulb) of two wires attach one set to the tabs labeled F2_N and F2_P. The other set can be reattached to the tabs labeled F1_N and F1_P. We chose to to solder the wires in place. First we tinned the tabs on the circuit board and then we tinned the ends of the wires with a small amount of solder. Once both the wire and the tab are tinned the wire can be easily soldered to the tab.
Shown with the wires removed.
The four wires highlighted (2 per tab) need to be removed from this tab. Two of these wires go to the left bulb and two go to the right bulb. It is crucial that you separate these wires into pairs depending on which bulb they attach to. To determine if you have a single bulbs pair of wires use either a multimeter set for continuity testing or a AA battery. With the multimeter read the continuity between the two wires. If there is a connection, both wires belong to one bulb. With a AA battery take the two wires you believe to be a pair and touch one to the top of the battery and the other to bottom. You should see a faint glow in one of the bulbs if you have both wires for one of the bulbs.
Plug the T4X decoder into the 9-Pin JST connector wired to the circuit board as shown in the image below.
Replace the shell, slide the couplers back in, and screw them in place.
To set the ditch lights to turn on with button 1 and alternate blinking with button 2 program the following CV values:
CV 51 = 42
CV 52 = 43
CV 36 = 4
You are now ready to run your SD70MAC with controllable ditch lights.
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