Cannot get my 3 Way toggle to work

Don't know specifically about the Atlas toggles, but in general the center of the 3 (assuming single pole here) terminals on the bottom is the common one ("input")that is then connected to one of the others when you flip the switch. 

So if your hot from transformer/main loop is connected ot the center terminal on the switch, the siding wire would connect to one of the other terminals, and the connection would be made when you flip the switch.

Also, most toggle switches are such that the direction you flip the switch actually connects the terminal on the other end when looking from underneath (which makes sense if you imagine the electrical connection as an extension of the switch handle down towards the contacts).

Hope this helps. 

Oh, and one last thing, when you say the ground on the spur is disconnected, I hope you just mean from the switch.  The outer rails should be connected to the same terminal on the transformer as the outer rails for the main loop.

-Dave

Correction, meant to say the power on the spur stays isolated with a fastrack block section that according the instructions the spur is isolated with the middle rail red wire disconnected .

Those fastrack block sections have 2 pairs of black ground wires and 1 pair of red connected from one end to the other with pre-fab connectors.

There are only 2 pairs of screws for each output and the one input.

The diagram on the instructions shows 3 rails though.

Is this the switch you mean?

If so, there are actually 2 connections on the side ("input").

Test to see whether you have the right connections with some alligator clips and a light bulb (bumper track, etc).  Disconnect the switch from the track before doing this experiment.

One side of light bulb to "common" on the transformer, other side to the top "output" of the Atlas switch(pick one of the 2 terminals).  "Hot" of transformer to the "input".  Set switch to On.  Apply some voltage.  If light bulb lights, you have right connections.  If not, power down and try other terminal on top "output" and repeat.  If light bulb never lights, you may have a bad switch.

This is starting to sound like your question from a few weeks ago, wondering what's changed?

Yep Dave, still struggling with it.....but.....I got it to work!

Would you believe I connected the power input to the wrong terminal!

Dang failing eyesight.