Have an Athearn SD40T-2 with the quick-plug feature, trying to install a SoundTraxx function-only decoder, manual does not state which pinhole on the circuit board is the #1 hole and I can not find a label for the hole on the board itself. I dont want to plug it in backwards, can anyone steer me in the right direction? Thanks, Nate.
I guess you mean a motor-only decoder, since as far as I know Sountraxx does not make a function only decoder.
Are you plugging in to the 9 pin or 8 pin? The 9 pin won't go in the wrong way, Looking into the conenctor ont he decoder, the the circuit board tot he bottom, green is on the left and violet is on the right. But it's keyed, it won't go in backards.
On the 8 pin connector, it won;t hurt if it's plugged in backwards, but the locow ill run backwards because the motor leads will be reversed. The pinout for the 8 pin plug is such that putting it in backwards won't short anything out and only results in flipping the rail pickups (which don't matter) and the motor wires, which will make the loco run the opposite direction. If it does, just flip it around.
If your DCC systm has a seperate program track, test on the program track first, see if you cna read CVs adn program the decoder. Only when that works should you put it on the full power main line.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
You are correct Randy it is a motor-only decoder I mis-spoke. I figured out which way the decoder fit into the pin holes but the problem now is is that the decoder is just a hair wider than the circuit board itself and the locomotive shell will not go back onto the frame so I will have to find a different decoder that is simply a little thinner.
Try tilting it ever so slightly. Which one did you use? The ones with the 9 pin are listed as slightlky narrower than the TCS T1 and I put a T1 in an Athearn RS-3 which definitely has a narrower hood than the SD40.
Yes that was attempted, I tilted it a bit and I ended up breaking one of the pins off lol! The actual problem is the molding, if you look up inside the hood itself you can see the inside gets narrower right where the decoder would be sitting so I think Im gonna try your idea with using a 9-pin plug decoder. You just plug that right into that harness right? Nate
Yes, the 9 pin decoder just plugs in tot he end of the little pigtail of wires. You have to remove the 'dummy plug' first - which you have to to use a decoder in the 8 pin socket as well. It's a little board that plugs in with a couple of diodes that control the directional lighting for DC.