Thank you all for the input. I do have a switch on my MRC Throttlepack 500 to go to Pulse Power, and to go out of it. It is a slide switch at the top of the switches. I have also used this same pack with other Bachmann locomotives, most recently with the RS 3, with no problem. I have also used it with Atlas O Dash 8 unit (2 rail DC) with the same type of set up with no problem. I suspect this to be a programming issue. I do have  anewer pack to try. I sill check and advise. SB

Hello. I just received a new GP 7 by mail from a reliable Hobby Shop. It says that it can run with DCC or just DC. I do not have DCC, but have regular DC. I put it onthe track last night, and it did not power up the motor.For a power source, I was using an MRC Throttlepack 500 and turned it to have the dial up, approxiimatedly 6 volts. We use this same soucre for two rail O Scale and it can power an older All Nations F3 unit, se we know the power is adequate. Instead, the lights went on both front and rear and they flashed  9 times, then rested, then flashed 9 times, then rested. This repeated to 9 to 10 flashes for a couple of minutes. We increased the voltage to full throttle, but same result. We tried changing the direction, but same result. When I turned off the power, I heard a faint crackle inthe speaker inside of the unit. Is this normal, or is there a way to get this to work. I really like the locomotive as it is in the Rock Island 1956 colors, and difficult to find elsewhere. Thank you.