Hmmm I agree I think it is something outside the engines that is not supplying power, I will test and see if there is power coming to the ECM this week… any suggestion how to zero in to see if it is a ECM or something external such as breaker or something.Normally it would only effect one engine, but I don't know how things are connected, or what voltages are at what locations and values. In short, not able to see what you see. Something is connected between the two otherwise it would not have changed anything on the other motor
Thank you.