Wiring a warning buzzer.

[Imarudedude]

Hello all! Im working with a 1993 90 hp Mercury outboard serial number 0D179573. The previous owner of the boat swapped the ignition and never reinstalled a low oil/overheat sensor. I would like to add one. I purchased a little 12v buzzer. I also have identified the wire in the harness up at the ignition that goes to the sensors (tan/blue in the attached wiring diagram I believe) From reading others posts it seems that I just have to attach the positive side of the buzzer to the accessory terminal of the ignition and the sensor wire goes on the negative side and when the sensor is activated it will ground and sound the buzzer? What do I attach the purple wire to? Also what is the function of the fuel enrichment valve in the diagram (yellow/black) and what should that be attached to? Thanks for the help in advance!

 

[sam am I]

The previous owner of the boat swapped the ignition and never reinstalled a low oil/overheat sensor.

I'm a little confused here.....swapping the ig. doesn't remove these two sensors from the engine, did the PO remove them off the engine when he did the ig swap? Or do you mean reinstalled a buzzer for these two sensors?

The previous owner of the boat swapped the ignition and never reinstalled a low oil/overheat sensor. I would like to add one.

I'm assuming you just mean the buzzer here and not the two different sensor devices "o" and "q"?

I just have to attach the positive side of the buzzer to the accessory terminal of the ignition and the sensor wire goes on the negative side

Correct and the "accessory terminal" (sometime also labled "I" for ignition )should have purple wire attached to this terminal normally.

Go here and here for more info

and when the sensor is activated it will ground and sound the buzzer?

Correct, the over temp sensor along with the low oil sensor (they are "OR'd" at terminal block "n") via the warning module can both ground and sound the buzzer. Also, the warning module by itself upon each power up (key being turn to "on") should also have a buzzing/beep sequence that indicates "all is well"

What do I attach the purple wire to?

See above

Also what is the function of the fuel enrichment valve in the diagram (yellow/black) and what should that be attached to?

It is a electric valve (with yellow/black wires) that when 12VDC is applied to it, it allows fuel to now flow through it and then into a specific port/area of carb's.......It basically floods the carb's with extra gas so the engine fires up better when its cold, sorta like dumping a cup of gas into your car's throttle body.

 

[Imarudedude]

Thanks a lot for the detailed response it is much appreciated. I should have some time to go through things tomorrow morning. I'll let you know how it turns out.

 

[sam am I]

You bet and plz do

 

[Imarudedude]

Well I'm pretty sure I have everything straightened out now.

Gas gauge is installed and working.
I also installed a voltmeter gauge to keep an eye on my battery charge. It reads roughly 12.5 with the ignition on accessory and 13.75-14 while the boat is running so I'm pleased with that!

I also installed the new warning horn. I didn't get the validation that the sensors are working though because I didn't get a "alls good" beep when turning the key.

I intend to just let the oil in the tank come close to running out (while keeping a close eye on it) to see if I get any warning beeps.

Thanks again for the help!

Now that that's out of the way i do have an additional question. I don't recall where I saw it but I remember reading that in the wiring diagram that I posted above the grey wire(#5) is the sensor wire for the tachometer. The console appears to never have had a tach only a speedometer, tilt/trim level and gas gauge.

If that is the case is their a way to test it to see if it's sending a signal before I purchase a new tachometer?

I've also had some trouble finding a reasonably priced tach. It also seems even harder to find one specifically for a 3 cylinder engine as most universal ones are for 4-6-8 cylinders.

If anyone knows a good place to find them let me know!

Thanks a lot guys I appreciate all the help!

 

[sam am I]

I didn't get the validation that the sensors are working though because I didn't get a "alls good" beep when turning the key.

Do you even know if the buzzer (or warning module) works like it is suppose to in your system yet?..........hmmm, what if it doesn't work at all? Shouldn't you test it somehow? What if the oil goes low and you have no clue the module or the sensor even works? What if the buzzer isn't good out of the box? Or goes bad down the road? Or you hooked it up wrong? Or the power wire to the buzzer fell off?

I'm pretty sure you actually should get a "self test/all is well" at power up.......It not only says "all is well" it also says to you "your warning module is okay", "your beeper and the power and ground path are all okay" too!!..........

This is why the "all is well/self test" is important to hear each time you power up, anything can happen/break/fall off/corrode/open, if not today, maybe tomorrow, you should always hear/listen for this before each outing.......

It's sorta analogous to your "lamp test" when you first turn and each time, your car's key to turned on, all the lamps light up for a sec so you can see/check none are burnt out, thus you'll know if something goes wrong you'll know at least the lights are going to be able to light up to alert you..........

Double check the module actually works and should or shouldn't do a "self test/all is well" and at least, ya might want to simulate low oil to assure that the low oil sensor, module and the buzzer all work....for this one time at the very least to be safe.

If that is the case is their a way to test it to see if it's sending a signal before I purchase a new tachometer?

Do you have a frequency function on a multimeter? If not, use the AC setting on a multimeter and you should see at least 10, 20, 30VAC or higher on the gray wire when running the motor.

 

[sam am I]

See pages 124 and 125

 

[Imarudedude]

Thanks for the info!

So today when I took her out I did get an audible beep when I first put the key to accessory. Then about two minutes later I got another quick beep beep after starting it to head out. I think it was because I had the motor trimmed up quite a bit (the oil reservoir is about 3/4 full) and it sounds for when it's half full I do believe.

Upon trimming the motor down and driving around for about an hour I got no other sounds. So I'm assuming that's a good sign.

I do unhook the battery every time I'm done with the boat for the day so I'm not sure if that has anything to do with why I get the "all good" beep Spuratically.

As far as the research I've done on the tachometer i believe I need one that has 12 poles/6 pulse. It has been hard to find one that is reasonably priced. All the ones that I found that fit that description are $70+. I was hoping to get out a little cheaper than that!

 

[sam am I]

Np,

I do unhook the battery every time I'm done with the boat for the day so I'm not sure if that has anything to do with why I get the "all good" beep Spuratically.

Shouldn't...Battery switches do the same (dis-connect the battery) and I've not experienced or heard of this. Check the the warning module's purple power and blk ground wire are tight/in good condition. (bullet connectors can get kinda crappy)

As far as the research I've done on the tachometer i believe I need one that has 12 poles/6 pulse. It has been hard to find one that is reasonably priced. All the ones that I found that fit that description are $70+. I was hoping to get out a little cheaper than that!

Sounds about right and If you have a freq meter for testing both functionality and that you have 12/pole, 6/pulse stator...... Then 6 pulses/rev * 16.67 rev/sec (1000 rev/min ) = 100 pulses/sec = 100 Hz.........assuming you can guess approx.1000'ish rpm's by ear.