Even though I'm a Digitrax user, I'd be the first to admit that using an LT1 to test decoders could be a dicey proposition for someone who doesn't understand electricity/wiring.
With any Digitrax "PS" decoder, you basically have to trace which color wire goes to which pin (not too hard) and then make the appropriate connections to those closely-spaced pins without shorting anything (can be difficult without the right setup).
If you're going to be doing a number of installs, I'd suggest a decoder tester that you can plug the decoder right into. NCE makes a basic one, and Ulrich Hobbies sells a couple of higher-end ones.
An easy way to "test" any DCC decoder is to put a 12V dc light bulb on the motor leads, Orange and Gray. The power leads of Red and Black go to the DCC track. Any throtle with address 03 will now run your 12V dc light bulb.
Bob Frey
Website: http://bobfrey.auclair.com
NOt wanting to be a pest here, but exactly or phyisically where do I hook the loose stripped wires on the LT=1 tester to a digitrac DH163PS decoder. I am not electronically savvy. I see the wiring diagram but do not understand it