Hello, I am a bit at a loss now with my setup as of Diagnostics mode the programming part should work as the two LED's are flashing but the main track LED's aren't lighting up/flashing at all either when sending <1> and afterwards a <D>. The motor shield is this one : https://protosupplies.com/product/l298p-motor-driver-shield/ and the site has some decent description with a test sketch. I loaded the sketch from the above site and tested both motors which work properly so the shield should be ok. The shield is installed on top of a Arduino Mega, the Mega and the shield having each its own DC power in and the link downwards to the Mega is disabled. I did look up everything and "think" that the original Arduino motor shield and this one should be pin compatible. I say 'think' because as i can't get any LED's flashing on the motor shield for the main track so there must be some pin issues i guess. I put a wire between pins 2 and 13 as outlined for having a Motor shield on top of the Mega and if i pull the wire the flashing actually stops so the LED's blinking are for the Programming track and the main shows no sign. If you have any ideas what i do wrong or how o test further i would be grateful. // Edit: Since i posted this first I loaded BaseStation Classic to see what happens and its the same behavior.