Found a few tips and LOYTOYS web site has recommendations. Read on.
" Life-Like Proto2000 GP60 and SD60M locomotives have an additional lamp added for the number boards which, as wired, causes problems on DCC (it does not adversely affect DC operation). Since the bulb is wired to the gray (negative motor) pin and the black (track pickup) pin, your DCC system will see this as a short circuitt. Disconnect the bulb from both pins and wire it to one of the function leads on the decoder to solve this problem. "
http://www.wiringfordcc.com/HO_P2K_GP-60.htm
http://www.loystoys.com/info/ll-ho-diesel-dec-sel.html
For relative ease of sound, try the Digitrax DH165LO. This has the plug for the Soundbug add-on sound module. The decoder replaces the factory board, and reuses the 1.5v headlight bulbs. The headlight outputs are 1.5v. A NCE P2K-SR also fits without bulb replacement, but does not have the sound option.
On the GP60, remove the number board light from the harness. It will cause a short. It can be reused, soldered to a decoder output function. I think it is a 12v bulb, but test it to make sure.
Mike WSOR engineer | HO scale since 1988 | Visit our club www.WCGandyDancers.com
WSOR 3801 wrote: For relative ease of sound, try the Digitrax DH165LO. This has the plug for the Soundbug add-on sound module. The decoder replaces the factory board, and reuses the 1.5v headlight bulbs. The headlight outputs are 1.5v. A NCE P2K-SR also fits without bulb replacement, but does not have the sound option. On the GP60, remove the number board light from the harness. It will cause a short. It can be reused, soldered to a decoder output function. I think it is a 12v bulb, but test it to make sure.
I've used the L0 decoders with great success on P2Ks. I am installing my first 165 with a Soundbug. Just as easy on the installation. The biggest challenge with the P2Ks is the size of the weight. There is precious little room for a speaker. I've seen others mill down the weight to add room for a 28mm speaker. I am trying different speaker options.
Engineer Jeff NS Nut Visit my layout at: http://www.thebinks.com/trains/
Tony's train Exchange is another great resource to find your answers. They install decoders into just about everything and then some.... www.tonystrains.com
You can email them with your question/s and they will get back to you quickly with what decoder you can use and what speaker is best for your loco.