Hmmm...by diagonals of channels 3 and 4, are you saying the same thing as the answer given by Elmod FAQ section below?

Question: The tank keeps not moving after installation of the Blaster. The turret works fine!
Answer: If a Blaster is installed, the engine has to be "ignited". Move the left stick to the uper left corner for HL-electronics (down-left for proportional) to turn the engine on and off.

If that's what you mean, I've already tried pushing the left (or right) stick down left...but the tank does not respond. [&o]