Yamaha 2 stroke key alarm issue

[muskrat1]

Engine: 2005 - 150hp Yamaha 2 stroke - oil injected.

Issue: Low oil alarm at key is "sounding" constant, while engine is running. With alarm on, engine goes in to limp mode.

1) Alarm at key appears to work (makes noise). Limp mode feature works when alarm is on.

2) Disconnected the main engine oil tank harness. Alarm still sounds.

3) Disconnected the remote oil tank harness, alarm quits. (Problem solved, so I thought). Ohm'd the old remote oil tank sensor, and float switch seemed to be intermittent. So, I purchased a new remote oil tank sensor.

While waiting for the new sensor to arrive, I learned a couple things:

a) With remote tank harness disconnected, engine runs great off the engine mounted oil tank. When engine tank gets low, alarm sounds. (which is good)

b) Learned the oil pump transfer switch works, as does the oil pump on remote tank. I can transfer oil from remote tank to engine tank, while engine is running with switch.

New sensor arrived:

Installed new oil tank sensor. Moment of truth...started engine. Key alarm is going off constant, and engine is back in limp mode. (New sensor did NOT fix it...grrrrrr!!!)

Now here is the oddity:

Removed new oil tank sensor from remote tank, so I could manipulate float, with engine running.
a) Float in "up" position (indicating good oil level), alarm sounds constant at key.
b) Float in "down" position (indicating remote tank low), alarm does not sound.

[muskrat1]

Did a pin out with volt meter at a couple joints. Both remote tank and engine tank are full of oil.

Key on - Engine off - Remote tank hooked up. An alarm sounds constant.
Key on - Engine on - Remote tank hooked up. An alarm sounds constant.

Key on - Engine off - Remote tank disconnected. Alarm sounds for 30 secs or so, then shuts off.
Key on - Engine on - Remote tank disconnected. Alarm sounds for 30 secs or so, then shuts off.

Voltmeter readings: Key on - Engine off:
Pig tail off engine harness in lower cowl.
Blue 0v, Black 0v, Blk/Red Trace 11.9v, Yellow 13v

Remote tank harness before tank.
Blue 0v, Black 0v, Blk/Red Trace 11.8v, Brown 12.8v

Voltmeter readings: Key on - Engine on:
Pig tail off engine harness in lower cowl.
Blue 0v, Black 0v, Blk/Red Trace 12.9v, Yellow 14.9v

Remote tank harness before tank.
Blue 0v, Black 0v, Blk/Red Trace 12.8v, Brown 14.1v

Key on - engine not running.
Remote tank pump wires after blue connector at the quick connects, before oil pump.
Brown wire 12.8V. Blue 0v.

Direct wire remote tank pump to battery. Blue to Neg, Brown to Pos = Pump runs. Also is pumping oil.

Did also notice there are two sounds at the key alarm, having different pitch. Call them Pitch1 & Pitch2.

Remote tank un-hooked, key on, alarm last about 30 sec, makes higher pitch sound (Pitch1).
Remote tank hooked up, key on, alarm never shuts off. Had lower pitch sound (Pitch2). Alarm will shut off, if I set float on remote tank sensor to "low" setting.

What did I learn....wires are transferring voltage. So, I will say no break in wires. Also, that pins in the connectors are correct.

[muskrat1]

Ruled out a couple items:
1) Determined remote tank sensor OK (tried new sensor in remote tank, no change to issue)
2) Also, remote tank wiring harness OK. (tried new harness didn't change problem)

Things to check still:
3) On board tank sensor

4) Trim position switch (Does this have any effect on a 2005 motor and the alarm at key??)

5) CDI box

Am I missing anything else, that could cause key alarm to be sounding. Keeping in mind, if I disconnect remote tank, alarm goes off at key.

[muskrat1]

Checked the following this morning:

3) On board tank sensor - 'suspect' sensor OHM'd good. Swapped with known 'good' sensor off my other boat. (which also OHM'd good) Neither sensor corrected alarm at key.

Also - drained onboard oil tank completely. Turned on key, not starting engine. Remote tank pump starts, begins to fill tank quickly. Pitch1 alarm sounds until on board tank hits bottom molded line (SW2?). Pitch1 changes to Pitch2, never shutting off. Pump continues filling onboard tank, until reaching SW1 fill mark. Pump shuts off automatically. Alarm still sounding at Pitch2.

Only way to stop Pitch2 is disconnect remote tank wire harness.

Repeated this process using both onboard tank sensors on 'suspect' engine. Both had same result. Both sensors worked fine on 'good' engine.

4) CDI box - swapped out with known good CDI box from my other boat. Did not correct problem. Put 'suspect' CDI box on other boat - works fine.

5) Swapped out complete remote tank system from good boat to suspect boat. Problem did not go away. Pitch2 alarm still sounds.

6) Trim position switch - I am thinking switch is fine, since tank is filling with key on. I unhooked trim switch connector, and alarm still sounds at key.

7) Tachometer - unhooked tach - alarm still sounds.

Have not checked:
Replacing key switch

Is there anything else, that could cause key alarm to be sounding? I am stumped.

[boats.net]

Need to check wiring harness, grren/red wire from engine oil tank may be grounded.

[muskrat1]

Need to check wiring harness, grren/red wire from engine oil tank may be grounded.

If you are talking about the harness from the engine oil tank sensor to the cdi box? If so, I replaced the entire oil tank sensor on the engine tank, and my problem did not change.


If you are talking about the harness from the cdi box, which connects to the 4 wire - remote tank harness in the lower cowl area, I need to check this still.

[boats.net]

The engine oil tank sensor will active alarm, the remote tank sensor will not, need to check wire harness going to engine tank sensor with green/red wire in it.

[rodbolt17]

what tachometer visual indicates are you getting?
my guess would be someone connected the gray bullet connector and your running a 703 box.
no sensors in that system, they are on or off switchs.
no audible alarms associated with either the remote tank switch(SWB) or the green/red wire.
if the blk/red or blue/red from the engine tank switch is grounded you get all alarm functions.
if the gray wire(bullet connected at the white 4 pin square connector) is grounded you get an alarm and an overheat visual.
thats why I ask what visuals are on the digital tach.

[muskrat1]

rodbolt

Currently, engine only has basic analog yamaha tach. Tach has no visuals or lights on it (other than panel light). Just a plain ole tach. No digital tach.

Tach hooks to the engine harness, via a smaller 'jumper' harness. Either 4 or 5 bullet connectors to tach. (from memory, dont have in front of me at the moment)

I do have access to a digital tach, from my 2870 pursuit, if it could be compatible or help diagnose.


Gray connector:
That someone, would be me, who likely hooked something up wrong. I will have to find that connection and see what I did.

I bought the motor used, to install on my boat after my original motor & controls were stolen. I purchased motor and everthing related to it. Engine harness, tach & tach harness, remote oil tank & remote tank harness, key switch, engine main power leads and a top mount single binnacle control box. Everything was a take off, from a center console boat going to be repowered to a 4S.

I installed on a 1900 Lund Pro V. Used all the same parts. Exception - I installed a new flush side mount control box, instead of the top mount binnacle.

[muskrat1]

This is the control I purchased new for the boat.


Part #6X0-48206-12-00

[muskrat1]

Rodbolt - could you share where the white 4 way connector is located, which you referred to? Is this the one near where the remote tank harness connects, and the main engine harness connects in the cowl?



Looks like I will have time to troubleshoot again this week

Thanks, Scott

[muskrat1]

Updated post since rodbolts reply above.


Still chasing issue. Replacing key assembly tonight.

[rodbolt17]

its not a key switch.
something is not connected properly.
overheat,low engine oil tank level and low voltage are about the only audibles you have.
at the engine,find the white square 4 pin connector.
find the gray wire,unplug the gray wire at the bullet connector and retest.
single engine yamahas have no alarm self test functions at key on.

[muskrat1]

Found the 4 way white connector.

It has gray/black trace wires coming into it. Followed back to the bullet connectors at the temp sensors. Other side of bullet, they meet pink wires.

Disconneted both temp sensors one at a time. NO change to alarm. As you stated, changing the key switch made no difference either.

Only thing that kills alarm is disconnecting the remote oil tank wire harness.

[muskrat1]

Question:

At the 4 way white pin connector. The wires do not seem to match up pin to pin. Is this normal?

As connected right now, which is how it was received as purchased. I have not messed with these.

Gray/Black female side to empty port on male side (plug in port)
Pink female side to black on male side
Green/Red female side to pink on male side
Green/black female side to Gray/black on male side