Thanks, it worked!  I did one other thing to improve my odds of getting it right.  I figured that there must be some standards for this stuff, and there are on the NMRA site.  The #8 socket is next to #1, and #8 is connected to the right side wheels.  My continutity tester located #8, and then it was easy.  Too bad Bachmann doesn't mark the sockets, or explain how to ID them, or give your suggestion:  Just try it.

Now if I can just get rid of all the shorts that this loco causes!  I am working on them one at a time.

Thanks, but no risk of damage if I get it backwards?

I am trying to install an MRC decoder and can't figure out where pin 1 should go in the receptacle.