Greetings all, I am building my first Tamiya in many years, the new M1 Abrams. I am at the point of testing the electronics. I tried an Airtronics RDS 8000 initially. After the configuration, all functions worked, except the main gun firing. (and yes I pushed the trim all the way up) I tried it multiple times, I tried adjusting the trim, no joy. I left it unplugged overnight and put in the receiver of a Tactic I pulled from one of my working Tamiya Tanks. It worked (yea) well sort of. When the main gun fired, light one, on the control unit, went red, and the tank shut down. I thought well maybe it's because of the settings from the Airtronics still there, so I pushed button to set up the radio, went through the setup, now everything (even Machine gun) works but the main Gun now doesn't fire. I am now stumped. Any ideas?

Try reading through Pcomm1.v2's Abrams build threads. There are known issues setting up the Abrams electronics. I believe he said Tamiya says to make sure all circuits are connected, even the headlights, before trying to fire the main gun.

Thank you all. Makes sense,