I bought this engine and passenger cars for $10, six years ago, at a garage sale.
It has ran poorly since then. Stopping and starting at will. It has been cleaned and torn apart a few times, by myself, with no real improvement. I cracked it open today and decided that I had had enough. I ripped out the circuit board that only works as a reversing unit.
I saved the switch from the model that turns on the reversing unit, to use as a on/off switch.
I then wired up plugs in case I ever want to disconnect the car again.
I then put some shrink tubing on the wires to keep everything clean on the outside. I drilled a hole in the bottom of the passenger car for the wires to pass through and secured them with a zip tie to prevent the wires from pulling out.
I then tinned the ends if the wires and inserted them into the plug of this RC car battery pack I had laying around. I ended up securing the plug and couplers with electrical tape to keep things running smoothly.
