I want to model BNSF trains that I've seen in the Powder River Basin and northern Colorado with 2 locos at the front and 1 at the back with a End of Train Device on the coupler. I'd be cool to know how I could put a flashing one on the front coupler of an HO scale locomotive.
Are you DC or DCC. If you're DC, then you're only option is to use a stand-alone circuit with micro LED. If you're DCC, you can add a single function decoder like the Digitrax TL1 and add an LED to power it.