Have 1989 twin 150 ETXF on 1989 Grady. Oil transfer pump on one motor not working. Sensor in engine tank and emergency switch don’t work. Low voltage (~7.5v) at pump. Also have 7.5v at oil pump harness connector in engine pan. So no issue with harness. Disconnected 10-pin connector in engine pan. Measured ~12v on red pin on male side of connector. Jumpered 12+ on male side to the corresponding pin on female side of connector. Then measured ~12v at yellow (key on) pin on female side of connector. So all good at the 10-pin connector in engine pan with key on. Seems that problem is with the brown wire In the oil transfer connector in the engine pan. Again, only about 7.5v across the brown wire and ground (connected directly to battery to eliminate bad ground). Tough to see where the brown wire goes from the connector. Seems to travel around to other side of engine to a connector that leads to oil control module. My next action is going to be to switch oil control modules between engines thinking that the source of the low voltage could be in the module. Anybody find any flaws in my troubleshooting or recommend something else before switching modules? Many thanks.