200txrp alarm help

[timswildlife]

I have spent a few weeks surfing this site and this motor has got the best of me. so finally decided to join for more help. Start off with thanks for all the help this site has given myself over the past few years.
Ok now my issue I just obtained a new toy 26 ft offshore boat that has sit for "9-10" years. salt water ran. She came with twin 200 yams 200txrp and a 200txrq the p is my problem child. Took boat for test run before buying and motors started right up cold and ran strong. Brought her home and we have alarms and issues. Started off with all 3 indicators blinking on the yamaha tach. So did a diagnosis and the aux oil pump was shot along with the trim tab sensor. swapped them out and oil alarm vanished. We took her out and filled the fuel tank up about a mile later same motor shutdown and won't start. Found a cracked fuel line under deck removed and replaced and then started carb problems and lack of fuel. Did a at dock carb spray down clean and got her running ok. Brought her home after a week took out for a test run and motor wouldn't fire finally got her running with a fouled plug and a bad fuel pump an over heating alarm and the tac wouldn't read the rpms. Since this happened a week ago I have removed cylinder head cover and exhaust outer cover cleaned the salt residue and reinstalled. checked pressure valve and seems to be fine. Have replaced thermostats along with impeller. Still having an overheating alarm and motor shutdown with just the red indicator lighting on the gauge.
So the 200txrp has new impeller, thermostats, aux oil pump, spark plugs, both fuel pumps, fuel lines, exhaust and cylinders cleaned of salt residue, trim tab sensor. My issue is over heat alarm constant even at start up got motor up to 4000 rpm and shut down. alarm is constant tack reading will work 50% of the time and only the over heat marker is lite up. Also tried unplugging both thermo sensors and alarm still sounds. any help will be grateful

[99yam40]

some motors had water in fuel alarm and low voltage alarm.
not sure if your does

I would be checking that the gauge lights up correctly when setting oil and over heat alarms just to be sure you are getting the correct signals and working as they should

[timswildlife]

new findings. i start up motor and alarm sounds. if i unplug the aux oil tank the alarm shuts off and the tach starts reading again.i have traced all the wires and can not find a short. could it be the brand new yamaha oil pump having a short? i hook the pump directly up to a battery and it works great. hook the system up and it won't pump at key on nor with the emergency switch. i did switch the cdi unit with the twin and i have the same issue. i have swapped the main oil tank sensor with the other motor and it made no difference. could the aux sensor have a short and tripping the alarm and stopping the entire system? i have gone over all wiring and everything seems to have the correct connecting and are connected tightly.

[rodbolt17]

I have no clue what an aux tank is.

typically there is a remote tank and an engine tank.

never heard of an aux tank.

there are no alarms that shut the engine off.

[timswildlife]

I meant remote tank when I mentioned the aux tank

[rodbolt17]

ok
I have beat precision blend to death.

at key on the brown wire at the remote tank is 12V positive, the blue wire provides the pump ground path via the CDI unit OR the toggle switch.
the black wire is the ground for SWB and the black/red is the path to the CDI that allows it to "see" if the switch is closed, sufficient oil for transfer, or open low remote tank level.
that brown wire splices into the yellow about 8" aft of the engine 10 pin main harness.
test it while loaded.

[timswildlife]

tested brown wire (at remote oil pump plug in) using a ground on motor and shows good voltage. Then tested brown wire to blue wire flipped emergency switch and had good voltage. Tested black wire to black/red wire and reads good voltage. disconnected emergency switch and plugged blue wire to black wire and gauge goes to just green light lite. plugged switch back in and went back to 3 lights flashing if i flip the emergency switch the pump will not run but the gauge goes back to just green lite. Disconnected each thermo sensors and plugged black wire into grey/black wire and gauge would just light the green indicator. unplug the remote tank and the motor runs good without any alarms and the tach reads the rpms until the engine oil tank gets low. Plug the remote tank plugged in and loose tach reading and a constant alarm. The system seems extremely simple on paper but has been messing with my head big time. swapped the main engine tank sensor with the other motors and has no effect, shows same issues. i wanna say its the sensor on the remote tank but i am just confused why grounding out the oil pump on the remote tank and or grounding out the thermo sensors would rid of the indicators on the tach. plus disconnecting the power into the remote oil pump set the gauge back to just green light. would completing a circuit elsewhere in the grounding system somehow complete a circuit threw the black wire to the remote sensor. I feel as if i may be way over thinking this system

[ausnoelm]

It is "doing your head in" because you are jumping all over the place, you don't need to look for "good voltage" you need a proper ground, and 12V at the right places, at the right time, dont get hung up looking for "shorts" in new pumps, follow Rodbolts troubleshooting to the letter.

[rodbolt17]

splatter gunning only works when you cannot miss.

precision blend is a stupidly simple system.
it has 4 switchs that are on or off.
the 4 switchs feed a digital logic con*****er.
the tach visuals just tell you what the con*****er "sees"

the engine tank has 3 switchs
SW1- commands oil transfer off when closed.
SW2 commands oil pump on when closed.
SW3 commands pump on,grounds the green/red wire to the tach for red lamp,commands audible and commands RPM reduction.
SWB is the switch in the remote tank.
when SWB is closed,float up, it grounds the green/white wire and the tach displays green lamp.
SWB open the tach internal circuit sees a loss of the ground and lights the yellow lamp the ECU sees it as low remote oil level and inhibits automatic transfer.

now if the con*****er sees SW3 closed(low engine tank level) AND SWB closed(plenty o oil). it commands the transfer pump on for 180 seconds and blinks all 3 indicators.

see how simple this is?
the system will basically troubleshoot itself.

[timswildlife]

Ok I cleared my mind. Tested brown wire to blue wire at main harness plug flipped switch I got 8.15 volts. Checked black-red to black at key on and reading 6.23 volts. Tested yellow wire on main harness from the plug at the Cdi grounded to a bolt on motor got a reading of 12.56. While Cdi is unplugged I tested black wire to black/red and got 3.87 then tested brown wire to blue and got 12.54 volts. Switched the Cdi out with its twin and got same readings. Compaired to its twin and getting readings of 12.61 brown to blue with switch flipped and black-red to black of 9.81 at key on. Shows I am not getting the 12 volts where I need it to be. I used a brand new fully charged marine cranking battery. Corroded wire harness at some place? I checked where the brown wire joins the yellow wireing cut this connection out and reconnected with no change in readings. But thinking that would have made no change in voltage supply in the swb supply

[boscoe99]

Ok I cleared my mind. Tested brown wire to blue wire at main harness plug flipped switch I got 8.15 volts. Checked black-red to black at key on and reading 6.23 volts. Tested yellow wire on main harness from the plug at the Cdi grounded to a bolt on motor got a reading of 12.56. While Cdi is unplugged I tested black wire to black/red and got 3.87 then tested brown wire to blue and got 12.54 volts. Switched the Cdi out with its twin and got same readings. Compaired to its twin and getting readings of 12.61 brown to blue with switch flipped and black-red to black of 9.81 at key on. Shows I am not getting the 12 volts where I need it to be. I used a brand new fully charged marine cranking battery. Corroded wire harness at some place? I checked where the brown wire joins the yellow wireing cut this connection out and reconnected with no change in readings. But thinking that would have made no change in voltage supply in the swb supply

Why are you checking for voltage on the SWB circuit? There should be nil voltage. That is the circuit that sends a ground to the CDI to tell the CDI that the switch is closed.

We need to back up a bit and start over tomorrow.