I have had the same thing happen with my Futaba FM RX. The only dif was my problem was after the Y. I had to add an extension to make it to the end of my 75!QUOT! wing. I too used a larger wire and the problem was fixed. I think the problem was too much voltage loss in the wire. I thought about using a 6v battery (5 cell) to see if that fixed the problem but I have not gotten around to it.