Hal.
It would depend on the vintage and what board is in the loco you have. P2k has several boards that was put in the locos. Sometimes you can put a TCS A4x or the T1X hard wired into it. Most of the P2K locos I have done were older blue box that took the T1X that I either hard wired in or used a short harness with the 8 pin plug. Then there are the PAs that took a long harness. Some P2K locos took the direct plug in DP5 decoders. I see they just released the new LL8 decoder for P2K. That may be the easiest to install.
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
I am looking at the Proto 2000 F7's , do not want sound, and want to install a TCS decoder. there web site does not list the decoder. Has anyone out there done this. I have a SW9/1200 and it used a T1A..
Thanks Hal