Are these engines like the P2K that require a special decoder because of the low voltage lights? I have quite a few Athearn RTRs (all DCC plug equipped) that are in need of decoders.
I have several Athearn RTR’s and they all have “DCC Quick-plug Equipped” on the box. They use the JST type 9 pin connector. I used NCE D13SRJ decoders in them with no problems. You need to pull the dummy plug out and plug in the decoder. I did not make any modifications to the lights.
So would a Digitrax DH123 work?
It depends on which version of the DH123 you choose - the one with the JST connector will work fine.
While it’s supposed to work with a decoder just plugged in, if it’s a recent run model, don’t be surprised if it doesn’t work as expected. I’ve run into several Athearn RTR locos lately with faulty circuit boards. Mostly it’s been SD45-2s which just wouldn’t run with a decoder until I got a replacement board from Athearn, or took out the factory board and hard-wired in a decoder.
Fortunately, none of the bad boards I’ve seen have been wrong in any way which harms the decoder-- the loco just refused to run with a decoder connected. With a replacement board from Athearn, they’ve run perfectly fine with the same decoder they refused to work with before.
I’m not sure whether they just got a bad run of boards from a subcontractor, or whether they might be switching over to lead-free construction and having teething problems, but the number of bad circuit boards I’ve seen lately has been disappointing.
I installed a Train Control Systems TC1 decoder in an athearn sd40-2 RTR a couple of weeks ago and didn’t have any problems. I use them because they cost about $10.00 and come with the “goof proof waranty”. I don’t like the headlight setup on the sd40’s, only the front headlight works and you have no control over it since it is conected directly to the motor leads. I don’t know if other Athearn RTR models are wired the same. Also you have to do some mods so the headlight doesn’t light up the inside of the cab.
Only the SD40-2s, GP40-2s, GP38-2s (anything that was origonally Athearn Blue Box) comes with the old style “bonfire” cab headlight. These are also not DCC ready. All the RTR products that are ex Railpower tooling (SD50, SD60, SD40, GP35, ect.) come with working front and rear headlights and are DCC ready.
Thanks for the help guys. I’ll stock up on DH123s the next time I’m at the LHS.
I am fairly sure that the SD50 and SD60 are new tooling, but everything else is correct.
For informational purposes, you can also buy the DH123AT which includes a special no solder required wiring harness for the Athearn BB and RTR units that still use a BB style mechanism. I’ve installed these in my old BB GP9’s and my newer RTR GP40-2.