yes i had that same thought when i saw the box on the left side, it would either be a capacitor bank or resistor bank but without getting a better look at it i couldn't say for sure so i didn't mention it. If there is a cover on it and he can remove it he may just find it has resistor coils in it, if so i would check those real closely. But keep in mind he said he could manually engage the contactors and the truck would run faster. That is why i was leaning toward the accelerator control circuits.