American Flyer AC300 Reverse Control Unit Gets Hot

Hi, I am new to this forum. I am restoring my childhood American Flyer train. I’ve cleaned it up, replaced the finger things on the control unit and the train runs ok. The problem is that the control unit coil gets very warm. I can keep the motor running continuosly at 6-7 VDC, but when I increase to 12 VDC,the coil gets very hot. Any ideas how I can remedy this?

Fred

Hi, you probably meant to post this on the Classic Toy Trains magazine forum. Classic Trains magazine is about the history of real trains.