I almost always hard wire every decoder install, even locos that have plugs on a board already, because so many of those factory boards are just odd.
A basic DCC installation is: red wire to right side rail pickup. Black wire to left side rail pickup. Orange wire to + motor terminal (which one is +? The one that was connected to the right rail when the loco ran forward in DC), grey wire to the - motor terminal. Make sure there is no contact between the rail pickups and the motor terminals other than these wires to the decoder. White and blue connect to the headlight, yellow and blue connect to the rear light, if there is one. If using LEDs, you need at least a 1K resistor for each light, doesn;t matter if the resistor connects to the white or blue wire. The blue wire goes to the + side of the LED< the white or yellow to the - side.
That's it. Plain decoders with wires like this also tend to be less expensive than special shaped boards. Hard wiring like this works in any loco, no matter if it's marked as "DCC Ready" - which is a mostly meaningless marketing term, there is no standard for what that exactly means - or not.
Sound decoders are exactly the same way, though sometimes a specific board replacement is a better option only because it leaves more room for a larger speaker and enclosure. But you can hard wire a sound decoder exactly the same way as a motor only decoder, just add 2 more wires that go to the speaker.
--Randy
Modeling the Reading Railroad in the 1950's
Visit my web site at www.readingeastpenn.com for construction updates, DCC Info, and more.
Yep, that'll work. I've got some of the DH126D's in old Athearn and Atlas locos. I'm no DCC expert, but I do hardwire my own decoders, and all installs are the same. Remember to isolate the motor from frame, and follow the instructions. After a few, you'll get comfortable with it, and you'll want to add LEDs for lights.
All this gives you some good soldering practice, as well.
Have fun!
Mike.
My You Tube
Im looking to expand my horizons and put my own decoders in. My questions is are there non-sound decoders that are universal and can be used in any manufacturer engine. I saw the DH126D by Digitrax is that able to be wired to any brand of engine. I have several that arent quick plug and older type and Id like to use an affordable non-sound decoder on those that arent quick plug. Im using them on HO scale. Any suggestions would be welcome.