94 Mariner 200hp EFI Alarm Buzzing

[jkillion]

Hi,

I have a 95 Mariner 200hp EFI outboard. Last time I went to the lake I didn't even get to fish because as soon as I turn they key I get a horrible buzzing noise and a High Temperature / Oil light.

It is a constant buzz and happens right when I turn the ignition to the run position. It continues to buzz after I have started the engine as well. Engine starts and runs fine, but didn't let it run very long because the buzzing was driving me nuts.

So, I am guessing since it happens right when I turn the key I am looking at either a bad high temp switch or a short somewhere in the alarm system. Sound right?

If I am looking at the engine, on the port and starboard head there are what I am assuming are temp sensors.

The port one has 4 wires, 2 with barrel connectors coming out of it (both tan and blue), one solid tan, and looks like a ground jumper. When I disconnect those barrel connectors, nothing happens to the alarm, it just keeps buzzing.

The Starboard one has a single tan and blue wire coming out of it that looks like it runs into a control box on the starboard side of the engine. This one does not have a bullet on it, so I was unable to disconnect it to see if it caused the buzzing to stop.

Which one is the one that causes the buzzing? And am I looking in the right place for these temp senors or am I off base?

Thanks for your help,
Jud

 

[ondarvr]

There are several sensors that can trigger the alarm, you just need to unplug them one at a time, if you unplug the last one and it stays on, you know the gauge is the problem. The other option is to disconnect the gauge and supply 12 volts to power it up, but no other connections, again, if the alarm sounds it's the gauge.

I've had gauges go bad, replaced it and the problem was solved.

 

[jkillion]

Thanks ondarvr. The only other two sensors that I know of that would trigger the alarm are the fuel in water (maybe) and the oil tank sensor. I checked both of those and it still buzzes. Is it the port or starboard sensor that causes the alarm?

-Jud

 

[ondarvr]

Is it the port or starboard sensor that causes the alarm?

​

-Jud

I don't have a list of what the codes mean for that motor, but overheat is normally a continuous sound, which is what the sensors on the head are for, so it could be either of them. A continuous alarm can be other things too, but oil is frequently a beeping alarm, so I wouldn't expect it to be from that area.

 

[jkillion]

Some more info.

I started unplugging sensors to no avail. Still buzzing. I think I have narrowed it down to the warning module (41470a22). Here is what I did.

1) unplug all sensors from the warning module (oil sensor, water sensor, rotation sensor and the green wire that looks like it goes to the coils. Only thing I left connected on the warning module was the purple wire (12v I assume) and the blue and tan wire that goes to a connection block that includes the signal back to the alarm and the hi temp sensor.
2) turned key, constant buzzing
3) disconnect the blue/tan wire going to the connection block on the engine. Now the only wire going to the warning module is the purple one.
4) turn key, no buzzing, but no noise either, not surprising
5) verify that the buzzer is working correctly by grounding out the signal wire to the buzzer to the engine block. Buzzer works.

So to summarize, all wires to warning module disconnected except the blue/tan and the purple gives constant buzzing. Only purple wire connected, no buzzing. Signal wire to alarm grounded out buzzing.

So, is this a valid test of the warning module?

The warning module itself has a part number of 41470a22. I can't find any information about that part number, just 41470a25.

Before I drop 275 on a new module, does the test seem valid and will the a25 instead of a22 work?

Thanks,
Jud

 

[Dukedog]

tha sensor on tha port side (4 wires) tan is for a temp gauge only.. it connects to a tan wire exposed on tha "male side" of plug in motor harness.. tan/blk are temp sensors for ecu, blk is ground.. sensor on starboard is over temp buzzer... if you trace it out it should terminate under a screw on a plastic term block along with tha blue/tan coming from tha module (thats where you can isolate both oiler module buzzer and tha over temp buzzer circuit)... disconnect blue/tan at that block and try key... get a buzzer then ya look at over temp sensor as suspect... no buzzer then ya lookin' at module as suspect.. all purple wires are 12v power circuit switch on by key....

jan... tha whole purpose of tha module is make any oilier/water warnin' sensor go beep, beep, beep instead of tha steady, irritating beeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeep of over temp... and provide tha initial self check beeps....

 

[Dukedog]

Some more info.

I started unplugging sensors to no avail. Still buzzing. I think I have narrowed it down to the warning module (41470a22). Here is what I did.

1) unplug all sensors from the warning module (oil sensor, water sensor, rotation sensor and the green wire that looks like it goes to the coils. Only thing I left connected on the warning module was the purple wire (12v I assume) and the blue and tan wire that goes to a connection block that includes the signal back to the alarm and the hi temp sensor.
2) turned key, constant buzzing
3) disconnect the blue/tan wire going to the connection block on the engine. Now the only wire going to the warning module is the purple one.
4) turn key, no buzzing, but no noise either, not surprising
5) verify that the buzzer is working correctly by grounding out the signal wire to the buzzer to the engine block. Buzzer works.

So to summarize, all wires to warning module disconnected except the blue/tan and the purple gives constant buzzing. Only purple wire connected, no buzzing. Signal wire to alarm grounded out buzzing.

So, is this a valid test of the warning module?

The warning module itself has a part number of 41470a22. I can't find any information about that part number, just 41470a25.

Before I drop 275 on a new module, does the test seem valid and will the a25 instead of a22 work?

Thanks,
Jud

3 and 4 pretty much tells tha story... module has gone south... i over looked (or when i read it it didn't register in this 'ole head) it............

try ebay.. 'bout ony thing that changed is tha rotation sensor part went away on later models............

 

[jkillion]

Thanks Dukedog.

In your opinion would it be better to just remove the VRO and premix the fuel and then get rid of the warning module all together, or does the warning module do other stuff.

My thinking is I can remove the VRO for next to nothing, change the fuel filter every year, and leave the hi temp sensor hooked up. That way I've always got oil, probably always have clean fuel since I replace the filter yearly, and get an alarm if I ever get into an overheat situation.

Of course this is only true if the warning module truest only warns about water in fuel and oil and serves no other purpose.

Thanks,
Jud

 

[Dukedog]

motor is gettin' a "little age" on it so goin' ta pre-mix is a good idea, so yeah. ... its strictly oilier connected with tha water thingy (thats kinda iffy) thrown in... it will also eliminate tha self check beeps when key is turned on..

[FONT=&quot]eBay item number:[/FONT]​

[FONT=&quot]291483323585

plus a pipe plug to replace tha fitting jus under starter.....[/FONT]

 

[jkillion]

Awesome, thanks. That just saved be 250 bucks!