[thebonecollector]

I consider myself mechanically inclined and have the curse of being able to repair/rebuild/diagnose and just flat out tear things apart to see how they work mindset. Same as a good number of people on here probably, BUT I have had this 1987ish Melex 3 wheel cart for about 10 years now and I cannot comprehend how this speed controlled, Potentiometer, contactor, solenoid microswitch, A2, S1, diode, resistor, series motor monster actually works. My brother and I have studied these many, many different versions of wiring diagrams from multiple sources and manufacturers and electrical specifications including the original Melex manual (and even talked to the guys in Poland at Melex on multiple occasions and still cannot clearly say that we comprehend how this machine operates. Can somebody....anybody please give me a schooling on how the system operates based upon this drawing that I spent hours cleaning up and coloring and studying so I might be able to understand the components and flow of electricity in this cart. I have the battery power, key switch, throttle (potentiometer) and mechanical operation parts down but how the current flows through switches that are not even technically being energized and a speed controller that absorbs excess energy that is fed by a solenoid and protected by a diode and capacitor that somehow tells a motor which way to turn is not clear. Based on the interpretation of this wiring schematic one thing that confuses me is how the Forward micro switch appears to be directly connected to the Reverse Sensing Device and as well how there is No Direct Negative Connection from the batteries to the motor. In my experience you need positive and negative connection to operate a DC motor. The speed controller and the F/R switch is the difference I know. BUT I do not understand the M+ M- A2 S2 S1 Microswitch Solenoid Speed Controller, diode basic functionality. Sorry for the long ramble but this thing is really getting the best of us and currently we are dealing with an upgraded (rebuilt) speed controller to 400 amp from stock 275 amp with new 400-1000AMP Solenoid and 4 smoked microswitches (waiting on 2 more to arrive) right now and just want someone with some expertise to help make us feel smarter than a 5th grader right about now..!