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86 Evinrude 70 VRO OMC Alarm

K

Kwalters

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So here's my issue: The engine itself is not overheating. My alarm is hit or miss, when it comes on it is a constant alarm, (not beeping as it would for the oil system) This happens at idle speed and can last for a while, however when I throttle up it usually goes away after a few minutes. The alarm will also sometimes just come right on when I turn the key on but not start the engine even after it has been sitting for a while and/or is cold! Sometimes it will even give a quick little beep like it's about to start alarming but then goes right away...I'm at a loss here. Possible fuel flow issue or just faulty sensory?
 
Disconnect the temp switch on the head and see if the problem persists? Then do the same with the oil pressure switch on the vro. While your figuring it out it will not hurt to premix the fuel in the tank 50:1 to protect the engine just in case the vro is taking a crap on you.
 
Pull all connectors apart and clean with electrical cleaner and put back together with dielectric grease. Sand all grounds metal to metal.
 
Kwalters said:
So here's my issue: The engine itself is not overheating. My alarm is hit or miss, when it comes on it is a constant alarm, (not beeping as it would for the oil system) This happens at idle speed and can last for a while, however when I throttle up it usually goes away after a few minutes. The alarm will also sometimes just come right on when I turn the key on but not start the engine even after it has been sitting for a while and/or is cold! Sometimes it will even give a quick little beep like it's about to start alarming but then goes right away...I'm at a loss here. Possible fuel flow issue or just faulty sensory?
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The warning horn warning you state is the one pertaining to overheating BUT you make a point that the engine is NOT overheating.... you go on to say that the warning horn will come on as soon as you turn the key to the ON position.

That first statement, regardless, is the usual indication of a failing water pump. If it were me, I'd make a point of making sure the pump is in perfect condition.

That second statement of turning the key to ON and having the horn sound off.... when the horn is sounding constantly, remove the TAN wire from the horn..... If the beeping stops immediately, one of the sensors at the engine is shorted OR that TAN wire is grounded somewhere.... however, if the beeping continues on with that TAN wire removed, the horn is faulty and will require replacing. NOTE: Cheaper horns (other types) are available... check around.
 
Water pump is new. And yes I know it's not overheating, I can put my hand on it and have had a thermometer gun reading fine. There is a fault somewhere and that's what I'm trying to figure out. I will go ahead and try and disconnect the head switch and see what happens and I'll clean all the connections up. I do not have a low oil switch on the VRO.

I've read some other posts and heard of some people having this issue in the opposite way that I have, thiers run fine in idle and then alarms when at higher rpm. Since mine was alarming at idle that's why I was questioning a fuel issue too...(I understand that there is no fuel alarm) however could this be triggering something, any thoughts?
 
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Some control boxes have a horn that sounds when key is turned on as a self test.-----It would have a circuit that you can see.----I am not there to inspect it.-----The horn itself may be defective.
 
What do you mean by.... "I will go ahead and try and disconnect the head switch and see what happens."

I've been in this line since 1960 and never heard of a head switch.
 
The temp switch is just a snap disk and wear out rather quick if the engine has been overheating in the past. The temp switch is normally open and closes when the engine gets too hot to sound the horn. The low oil and vro switches are normally closed and open when there is oil in the reservor or pressure from the pump. The two oil switches are two wire the ground wire must be good. When you turn the ignition on you should have battery pos to all three switches.
 
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