Dual Relay $19.95 Dimensions: 1.5" x 1.2" (38 x 30 mm)
Connects to a Switch-It or Switch8 decoder to provide two SPDT or
one DPDT relay output for switching up to 2 Amps of power.
Control polarity of “dead frog” turnouts
Automatic Reverse loop control - MAXIMUM 2 AMPS
Turn track power on/off in staging yards
Provide isolated turnout position information to signaling or computer control systems
Wiring an AR loop using relays can be confusing. Use the attached diagram I pulled from the manual.
The best way is to think of it as 3 separate items. You have an INPUT, a NORMAL track OUTPUT, and a REVERSING track OUTPUT.
Look carefully at the diagram and note that the NORMAL track output and the REVERSING track output are on OPPOSITE SIDES of the board.
The normal output handles the entire layout EXCEPT for the AR loop.
Since you have to add 4 jumpers to follow the diagram, you might find it easier to wire up the jumpers first then add the rest of the wiring as a separate step.
Color coding the wires will also help.