Logo
FULL SITE MENU

1985 Evinrude 90 HP oil warning horn

K

kinni-kid

New member
I have a 1985 Evinrude 90 hp V4. I am doing some maintenance and upon investigation, I noticed that my low oil warning horn is not working. I have tested both engine heat sensors and nothing happens. I've owned the motor since 1992 and I have never heard any warning beeps, even when I turn the keep on initially.

Is there a way to test the horn? I have removed it and tried to test it with a 12v battery, nothing. Also should I just replace the horn? Everything else seems to be working fine, motor runs good.

Any you could help me with would be great. The horns seem to be quite pricey. Will the current horn that the websites are selling fit my control unit?

Thanks!
 
The horn should have 12 vdc on one wire and the other wire from the senders (tan w/blue stripe?). The senders are grounded by their activation...low oil and overheat. Grounding test of either sensor should activate the horn. If not check for 12 vdc on the one side of the horn. If it is there then replace it w/any similar 12 vdc horn...it doesn't have to be a Merc. horn.

My boat has a dash mounted keyswitch. No module to test the horn at start when turning the key. I added a test button under the switch to test the horn circuit. I had the same problem and the solution was adding 12 vdc to the horn. The circuit to it was dead. I just tapped into a purple wire under the dash.
 
kinni-kid said:
I have a 1985 Evinrude 90 hp V4. Is there a way to test the horn?
Click to expand...

With two small wire jumpers connected to a battery. Connect the horn black ground wire to battery negative (-), connect battery positive (+) to the horn terminal closest to the horn ground wire. The horn should sound a beep for only one second.

Remove the jumper wires from the horn.

Now, connect battery positive (+) back to that horn slide on terminal closest to the horn black ground wire. Then connect battery negative (-) to the remaining horn slide on terminal. The horn should sound constant and steady.

That horn is very overpriced in my humble opinion and there are alternatives including one that is available at Radio Shack. Unfortunately I don't have that information at my finger tips but I"m sure other members will jump in here to advise you.
 
So... If I've tested the horn and it only makes a few "clicking" noises when attached to a 12 v battery (purple lead connection to "+" terminal and gray lead to "-") then it's possible that the either the horn is bad or the circuit is dead, correct? If I put a meter on the the purple and gray leads with the horn connected and turn on the key or ground out a sensor, I should see 12 volts, correct? If I don't see 12 volts, then I will need to tap into a power source somewhere to provide power to the beeper constantly as the sensors, when activated, complete the ground for that circuit. Is that correct?

I was able to find an OMC horn for $35 on this website, so I ordered it just in case it's the horn. If the horn is okay, then how would I go about trying to trace the dead circuit?
 
I just took the time to advise you how to test the warning horn....

Why are you branching off on some other "incorrect" way to test it?
 
If the horn is okay, then how would I go about trying to trace the dead circuit?
Click to expand...
W/the key on check for 12 vdc on the hot side of the horn. W/the key off check for continuity from the switched side of the horn to the wire junction on the engine...just follow the switch on the engine to a junction and check it between the two points. If you have 12 vdc on the hot side and continuity on the switched side then the horn is shot.
 
joereeves - sorry I didn't mean to question your advise, but but the testing method you described does not accurately reflect the horn that is mounted in my control unit. The horn I have has 1 pair of contacts, a gray wire is attached to one and 2-purple wires are attached to the other. There is no "black" wire or ground to speak of. I appreciate everyone's help in assisting me with my problems.
 
kinni-kid said:
joereeves - sorry I didn't mean to question your advise, but but the testing method you described does not accurately reflect the horn that is mounted in my control unit. The horn I have has 1 pair of contacts, a gray wire is attached to one and 2-purple wires are attached to the other. There is no "black" wire or ground to speak of. I appreciate everyone's help in assisting me with my problems.
Click to expand...

That's the old style warning horn that doesn't have the initial self test (1 second beep) whenever you turn the key on. I can now understand why you were branching off into a different test.

To test that horn, simply have 12v applied to one terminal while having the other terminal grounded.

Note that the "GRAY" wire is a sensor lead for the tachometer. The sender wire for the overheat horn should be TAN.
 
Completed all the testing over the weekend. I have 12 volts on the hot side of the horn with the key on. I also have continuity with both engine temp sensors, oil level gauge and oil pump at the tan wire on the horn. Based on all that, I'm convinced the horn is shot. I will install the new horn when it arrives and follow-up with the results.

Thank you!
 
I just found out the horn that I ordered from this website for $35 is not available (fancy that). I do not want to spend $70 for the udpated OMC horn, so can you tell me what a replacement would be? I have found several 12 vdc horns/beepers. Most of the horns/beepers I've found are in the 10 mA to 35 mA range, would these work?
 
Some members have purchased some kind of horn at Radio Shack and apparently are quite happy with it. Hopefully they'll jump in here and tell you which one it is.

You can use a two wire horn and simply insert another wire that will run from the TAN wire to one of terminals of a push button and another wire from the remaining terminal of the push button to ground. Pushing the button makes the horn sound... a self test feature. ($10 or $15)
 
Well, I've installed a non-OEM 12vdc 2-wire horn per you instructions above. When I turn on the key to Accessory position (before the starter is activated) I get a constant horn sound. I've disconnected the two temp sensors as well as the oil tank ("low oil) sensor and I stil get the horn sounding. Then I disconnected the oil pump tan wire and the horn would stop. The test button works fine.

does this mean that the oil pump is shot? Or will that constant horn sound go away with the engine running? Please help if you can!
 
When turning the key ON (engine not running)... If the horn sounds constant with all the sensors connected and stops sounding when the VRO electrical plug is disconnected, then yes... something is wrong with the VRO pump.

Having the engine running would make no difference.
 
Back
Top