oil transfer pump is energizer bunny(it keeps running and running)

Hi, I have a 1987 Yamaha 115ETLH, with the key turn on and the main tank is full the transfer pump will not turn off. If I raise the engine past 30 degrees it will shut the pump off. I have a Seloc manual for this outboard. In the v4 section it tells you to unplug the main tank oil sensor from the harness and the checks are with the blue/green wire and the blue/white wire. If you jump the harness it will turn pump on and off. While my wires are Red, Black, White, And Brown. I'm trying to troubleshoot this system to replace the needed part only, the book is not helping, this is my first post but I read alot of useful information on this site! Thanks in advance Don

[jb123]

sounds like your main tank sensor is bad or stuck down, simulating low oil, hence the filling. pull it out, ensure it moves freely, the turn on system and move float up and down and see what happens.
what gauge do you use, digital or analog? no warnings on gauge ?

[jb123]

ALSO, possibly a bad oil harness and tilting makes or breaks the signal...???

Hi JB123

Thanks for the reply; the warning gauge is the lights on tach. The green light is. The main tank sensor gauge is the magnetic float with the "H" on top of sensor being it’s a hold circuit sensor. When I ground out the white wire on the sensor and move the float to the top I go from open to showing some resistance on my multimeter. Also checked the other wires and moving the float to other areas on the float will give readings. Tilting my engine past 30 degrees turns the pump off, there is a mercury switch so you don't get a false float reading and 2 stroke oil overflows when engine is tilted. On the pump positive 12 volts is supply to the pump and grounding the pump is the control. I checked the harness to make sure it isn't grounded out before the control unit, seems to be OK. Looks to be a bad control unit, hoping I didn't miss anything. Any other checks on this system? The control unit is 177.00 plus shipping would hate to replace it and not be the problem,

Thanks Don

I also had the main sensor out of tank, wires connected, main tank very full. move the float by hand and the pump keeps running.

I ran the test that JUST-IN-Time sent me and the problem was the 2 stroke control unit. I purchase one from this site (excellent price) and installed it yesterday. My motor being a 1987 and Yamaha updated this control unit, it’s not the same as the old style. But Yamaha gives instructions for the changes. Anyway I tested today and works fine.
Thanks to all that posted, Don