I would take out the factory board and use a board replacement style decoder. Tsunami 567 would be the one you want, for the best sounds available at the current time. The P2K bulbs aren't the greatest, replacing with Miniatronics 1.5 volt 15ma bulbs in the housings will look better. The Tsunami board is all set up to use these bulbs, no need to cram extra resistors somewhere. Just have to figure out your speaker arrangement.
The P2K board has all sorts of extra gobbledygook on it. The engine will run better without it. Just hook the wires up directly to the decoder.
Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com
I have a P2K SD7 Dcc ready (8 pin plug) and wonder if any of the recently released plug-in sound decoders by various manufacturers will work, and particularly which decoders ( motor or sound) will work with the P2K lights. Or, is the lighting problem even still an issue in dcc ready P2K's?
Mike