I have wanted to test those wire to control speed and revers rotor pump, but have not yet. If no one can tell you what the voltage should be on the wire for revers in the next two day I will have some time to check on mine. I don't have the book here but I'm sure there is one wire for revers and 2 or 3 for forward. On the revers line I think it should have 12 volts, if 12 volts is present then suspect internal of pump, I haven't seen diagram of pump but there would have to be some kind of selonoid for revers. On selonoid you test for with ohm meter for 10 to 100 ohm from input wire to ground, if that is ok it would be mechanical.