I made a few simple modification to the circuit board on my 201 to enable the cab lights to work. I am using a TCS 6 function 21 pin decoder but this modification will work with any 21 pin 6 function decoder. You will need 2 resistors, a soldering iron, solder and a pair of tweezers
In this picture we have the circuit board before I start work
First start by removing the diodes and resistors with your soldering iron. The ones you are looking to remove are marked R1,R2, R3, R4, R5, R6, Q1, Q2
Then take your 2 resistors and solder them where I have in the picture below. Now you will have F0 side lights. F1 full beam #1 end. F2 full beam #2end. F3 cab light #1 end, F4 cab light #2 end
Some decoder manufactures tell you to remove the suppressors fitted to whatever loco you have. On the MM 201 these are the green bulb (black,red,silver stripe on them) shaped devices either side of the decoder.
Remove these with your soldering iron and with your tweezers pull the red and black wires across and resolder job done
I hope some of you guys find this helpful its not hard to do even if you don't have any soldering experience and it enables you to buy any 6 function 21 pin decoder