Blue box athearn and Railpro

[IDRick]

For my next layout, I would switch from a very basic DC powered layout with atlas components to Railpro.  My locos are mid 90's vintage (5 blue box athearn and 2 P2K diesels).  I understand that I would need to add a harness to upgrade the athearns to accept a DCC or Railpro decoder.  Many videos show a solderless Digitrax harness to convert the Athearn blue box locos but sadly they are no longer available.

My questions:

1) is there a replacement part for the digitrax harness?

2) is there a concern about the current draw on the older athearns relative to railpro installation/operation?

3) is there an easy fix to reduce current draw by the athearns?

Thanks!

[rrinker]

 All the Digitrax harness is is the wires soldered to the top and bottom motor clips. Easy enough to do yourself. The clip that replaces the headlight bracket is a bad choice for connecting to the chassis side anyway, that bracket is just loosely riveted on. A better way is to drill a hole and tap it for a brass screw in the frame, and solder the wire to that.

                                     --Randy

 

[riogrande5761]

But don't you need to isolate the motor from the frame in the Blue box Athearns in addition to the Digitrax harness?

[IDRick]

Thanks Randy.  I liked the plug and play aspect of the harness.  So many made a video of that approach that it seemed to be good idea.

 

Rio, yes one does need to isolate the motor from the frame.

[rrinker]

riogrande5761

But don't you need to isolate the motor from the frame in the Blue box Athearns in addition to the Digitrax harness?

 

The bottom tab has the contact tab clipped off (or they just used two toop tabs - same thing). Not a bad idea to put a layer of Kapton tape in the bottom before putting the motor back, but the mounts are plastic and no screws are used.

 For a design that originated in the 50's, long before DCC or even the forerunner of them all, Astrac, was conceived, they are pretty easy to convert. And after they switched to the gold motors, they don't really draw excessive current. Back in the day before Spectrum or P2K, for a few bucks more than the junky train set locos of Bachmann and Life Like you could get an Athearn BB loco which was superior in almost every way.

                                    --Randy