20-3647-1 Light Mikado no power to locomotive

I do not see which wire is broken on left, looks like heat shrink?  Anyway you need to trace the wires for sure.  Normally black to black.  The engine should send center rail pickup over one wire, and right side wheel on the other.  The left side chassis ground wheels of the engine make contact to tender via the drawbar metal pin that touches tender post.

Look at the solder joints on switch, one should show being broken, or have strands of wire still attached.  G

Could be a bad switch as well, I've had several of those cheap switches let go.

There are no solder joints not connected on the 3/2 rail switch,  How can I solder jumpers on the switch to make it 3 rail only.  I have already soldered the DCS wires together to make it dcs only.

Bruce, your a tech.  That black jumper wire does no good on the switch with out an input.  So most likely your upper left black solder joint has a broken look to the solder where the loose black wire would join the jumper.  BUT trace it out.

As far as making it permanent 3 rail that is simple.  Get the center rail pickup wires and the ground wires going to the correct place.  I normally go in the engine and repurpose those right side wheel wires to AC ground with a jumper to the chassis.  Then both engine and tender provide an over the wire ground.

Basic wiring stuff here.   G