Hi - I can't get my 670's nor 26671's to work according to the diagrams. Of course, bought them from ebay, so they are probably worthless (see? I'm learning) but I think some of the problem deals with "this whole thing is a circle." I see warning that if I hook up two of the aforementioned track trips that a wire needs to be run between them - I think this is because "in a circle" one set of needed track insulating pins makes one "dead zone" with power on each side, but when you put 2 "dead Zones" in the circle now you've got a big big dead zone between them. So that was my hint. I'm wiring my wye legs and there's no power to one side of it. I have a power clip there (so both sides of the wye leg have power), but when I turn the switch from 2-train mode (power switches when the frog is thrown) to "power both sides all the time" the sliding switch button does not appear to work. I have 3 light bulbs I can attach to the track to quicky see if power is on. Quickly checking, I found one of my switches does work in "power both sides all the time" mode, but the one in my wye as well as another I placed there to also try both won't go into that mode. Is this common? I have my layout down, I hate to think I've got to tear it up to fix these switches.
For tesingt 670's and 26671's, I believe they are "current drawing" devices, they sense the current draw of the engine and close a contact. To test these, my first thought is to use the variable AF transformer power and for current draw use that 10 ohm resister that's used on sidings so to maintain a small voltage so the reverse unit remains energized while the train sits on the siding - preserving direction. So I'd go from the hot rail to one post of the device, then from the other post to the resister, and from the resistor to the base rail. That should put current through the device and I can check to see if the relay closes, again probably using light bulbs.
Any advice welcome - Tom