John and Sinclair are correct. Try a simple test: take two straight pins, plug into the middle two pins of the tender tether. When looking at the top of the tether, the red lead (center rail) is on the left-center, black (common) is right-center. Attach track power and apply 10-12 volts. Does the tender come alive? If not - your tether is lacking continuity. If the tender comes alive, I would suspect the outer two wires, white and yellow are not making contact with the locomotive. This would verify you have a faulty tether.
I have repaired numerous ps1's with defective tethers.
bruce
