@endless tracks posted:I intend this to be 3-rail. There is no 2/3 switch. Only a volume pot and the DCC/DCS switch.
The (scant) instructions said for 2-rail , remove the rollers and move the switch to DCC.
If you're trying to find this with the DCS system, regardless of 2-rail or 3-rail, the switch MUST be in DCS! If the switch happens to be defective, the default open is DCC, so maybe it's just bad/flaky switch.