91 Yamaha 150 oil pump always running

[Mikeys250]

I have searched as much as I can and have learned how this system works pretty well. But in kinda stuck on this issue.
The motor is a 90
or 91(model number plate is missing) Yamaha 150 precision blend. First I had no power to the remote pump and checked power all along oil harness with nothing and decided to connected the yellow wire in main harness (key on 12v) that I was told I didn't need to hook to the universal key switch I am using. This got power to the pump but it is constant power, pump runs when hooked up regardless of oil level. I ohm'd the remote float switch and it is good. The main tank float seems to be my problem but I want to be sure its not the control unit.
This is where I get stumped, by ohm'ing the top side float I have infinite resistance for the bottom and middle switches(open circuit) but top switch meaning tank is full and should kill pump gives me resistance of about 20 when it should, then infinite when the float moves down.
By following a trouble shooting article I found it said to ground the white wire from float and if the pump stops then the control unit is ok but float is bad?is this correct? If the float is bad then why did it put motor in limp mode when the main tank was about 1/4 inch below the bottom line?

[99yam40]

oil pump should have 12 V+ power any time key is on.
Module controls the ground from what I have read.
need to go through the complete troubleshooting procedure to make sure all 3 level switches function properly not just the top one to see if there is a problem with switches, wiring , or the module

[rodbolt17]

at the remote tank pump.
you should have 12v when the key is on between the brown wire and engine ground.

the blue wire is grounded by the oil control module,or the emergency switch.

if the blue wire is shorted to ground the pump runs.

on the engine tank.
top switch is SW1,sw1 closed turns the pump off.
sw2,2nd position closed turns the pump on.
sw3 bottom position,turns the pump on,sets the audible and sets rpm reduction.
.
I have extensive posts on trouble shooting this simple system.

[Mikeys250]

oil pump should have 12 V+ power any time key is on.
Module controls the ground from what I have read.
need to go through the complete troubleshooting procedure to make sure all 3 level switches function properly not just the top one to see if there is a problem with switches, wiring , or the module

Going off of the continuity of the float switch it is not working properly but when it put the engine into limp mode it made me think it was working.

at the remote tank pump.
you should have 12v when the key is on between the brown wire and engine ground.

the blue wire is grounded by the oil control module,or the emergency switch.

if the blue wire is shorted to ground the pump runs.

on the engine tank.
top switch is SW1,sw1 closed turns the pump off.
sw2,2nd position closed turns the pump on.
sw3 bottom position,turns the pump on,sets the audible and sets rpm reduction.
.
I have extensive posts on trouble shooting this simple system.

I was hoping you still posted here. Your post pretty much taught me how the system works. I have 12+ to brown and blue is always grounded so could that be control module or float switch? there seems to be something weird about my issue where the float switch works for RPM reduction but when I check sw3 with DMM it shows and open circuit with float at the bottom. How do I determine if the control module is bad? How do I know for sure its the float?

[ausnoelm]

I think if you read Rodbolts reply "carefully" and use you meter, the answer is right there, do not "poke around" there is only a couple of places he told you to check, testing everything you see will throw you off track, remeber we are talking simple switches here, on or off, nothing in between, easy to test.

[rodbolt17]

some engine tank switchs are polarity sensitive, use the diode check function and reverse the meter leads.

either the engine tank switch 2 or 3 are closed,sw1 wont close or the oil control module or the blue wire is shorted to ground.
all can be easily isolated.

[Mikeys250]

We'll folks I really appreciate the help but I went out to follow y'all's advise yesterday and dang if the system isn't working as it should. Pump kicks on at sw2, goes to limp mode at sw3 and stops pumping at sw1. This is why I hate electrical components. They have a mind of their own. I ran it for about 2 hours yesterday and all seems to be well.