I acquired some fairly new InterMountain locos with the decoders removed and 21-pin connection sockets. I have some 9-pin decoders from some Athearn locos sitting around, so I purchased a few TCS 21/9 pin adapters. When I hooked them up, the train seemed like it was going to run, then stopped. I got the same issue with 2 decoders and with 2 different 21/9-pin harnesses (and 2 different identical locos). The decoders work when plugged into a regular 9-pin Athearn loco. I understand that I could just buy a new ESU decoder, but now I'm interested and what to understand what's going on.
Does anyone have any insight as to why a standard 9-pin decoder connected using a TCS 21/9 harness to a fairly new InterMountain loco would not run?
Are the connections working loose after the loco starts running? There's no real reason this shouldn;t work, the motor and track wires are standardized in both plug types, so an adapter device like that should be a no brainer to make.
TCS and others have 21 pin motor decoders as well, you don't HAVE to use an ESU one. But they are very good, even the non-sound ones.
--Randy
Modeling the Reading Railroad in the 1950's
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