I've spent many hours working on the Pendulum reversing units and they can be one of the most frustrating things to try to repair. The first thing I do is completely remove it from the motor, inspect the wiring and run continuity tests with a standard multimeter. Be careful not to lose the tiny nuts that attach the wires to the board. If the wires are good but there are cracks in the wire casing I cover the cracked parts with heat shrink tubing. Next I check the thin metal reed which contacts the steel arm that moves up and down when power is applied to the motor. The reeds are almost always rusted which causes bad continuity so take some fine grit sand paper and sand it until it's shiny and you can see that good contact is being made with the metal arm. The curved brass lever that also makes contact with the steel arm should hold it firmly in place against the reed when you pull up on it. This will make the loco go forward only and pushing the lever down will let the reverse switch cycle to forward and reverse when voltage is applied. Next I use a small filed down flathead screwdriver to pop the board with the pendulum switch assembly out of the brass housing. Now you can see the back side of the switch and at this point I clean it with contact cleaner and make sure the little spring isn't bent or broken. Now is where the fun begins. I don't usually remove the center nut on the the front of the board and disassemble the whole thing. What I do is I spin the pendulum so that you can see the little delicate "fingers" which are in between the switch and the board and using the same fine grit sand paper I carefully sand the end of the fingers which make contact with the metal circle terminals and then I sand as best I can the circles themselves so there is no corrosion or gouges. Then I slightly bend the fingers so they make firm contact when they slide across the metal circles. Next you spin the pendulum to the opposite side and do the same thing. After this I inspect the solenoid plunger and spring, again using fast evaporating contact cleaner (I use CRC brand) to clean it. If you don't have contact cleaner you can use 91% Isopropyl alcohol or even a little white vinegar. Make sure you clean where the plunger enters the solenoid. Do not use any type of lubricant like WD-40 on any part of the pendulum switch components or solenoid as it will cause it to gum up and will work worse then when you started. After you have done all this use your screwdriver and ease the board and switch assembly back into it's place in the brass housing making sure the brass actuator arm is inside both halves of the switch assembly. If you pop the board back into place with the actuator arm outside of the two halves you will not be able to get it in without bending it and will have to pop the board back out again. Next flip the reverse unit upside down and using your little screwdriver push down on the brass actuator arm and you should see the pendulum switch cycle smoothly back and forth. Reconnect the wires to their respective posts on the front of the board making sure the tiny nuts are tight and that the wires do not touch each other. If those original solid wires were bad and you replaced them with stranded wire it's extremely hard to wrap them around the posts and tighten the nuts without the wires unbraiding and touching each other. I get around this by crimping on small fork connectors which work nicely but they must be small enough not to touch the other posts. At this point install the whole unit back into the motor and replace the screws. Set it on the track, make sure the curved brass lever is pushed down so it'll cycle forward and reverse and give it a good 10V of power from your transformer. Your Super Motor should take off immediately, run it around your track a few times, let it come to a stop and give it another good 10V of power and the switch should cycle completely and the motor should take off in the other direction. Congratulations you have serviced a pendulum reverse unit!!! I'd say this procedure works 80% of the time. If your still getting a short it's within the other motor wiring (brushes, field, collector plate, headlamps etc. If the reverse unit still doesn't cycle every time I would give it "exercise" and just keep cycling it back and forth. Sometimes it'll just start working perfectly and other times there is nothing you can do except swap out parts from another pendulum unit until it works correctly. Otherwise there are usually a few refurbished original units for sale on ebay. Best of luck and I hope all this information is helpful for you or anyone else.
TinplateDave
