Overheat alarm test

Brew2

Chief Petty Officer
Joined
Jan 12, 2004
Messages
427
Hi,<br /><br />1986 Evinrude 140...want to test warning horn...have read in other posts that I need to disconnect the wire from one of the overheat sensors and then ground the wire to the engine block. <br /><br />My question is, how does one disconnect the wire from the overheat sensor? I see the tan wire going into the back of the cylinder, but don't know how to disconnect it in order to ground it. My manual wasn't much help here. <br /><br />Thanks,<br /><br />Brew
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: Overheat alarm test

Follow the brown wire from the head forward. You will come to a connector that is under a tube like cover. Slide the cover either way & disconnect. This is the way OMC did it. Many have been changed over the years during a service or repair so yours may not be exactly this way. If you have a test lead with a sharp point you may be able to test it by penatrating the insulation of the brown wire rather than disconnecting it.
 

Solittle

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Apr 28, 2002
Messages
7,518
Re: Overheat alarm test

Oh ---------- and you need to turn the ignition key to on to do the test.
 

ob

Admiral
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Aug 16, 2002
Messages
6,992
Re: Overheat alarm test

Brew,Bare in mind that the grounding of the tan temp sensor lead to ground is testing the operation of the overheat warning alarm and circuit.It does not verify that the temp sensor itself is performing its job.That is a separate test that requires the sensor be heated to a specified temp and testing whether it will complete the circuit for alarm.
 

Brew2

Chief Petty Officer
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Jan 12, 2004
Messages
427
Re: Overheat alarm test

Thanks guys!<br /><br />Cheers,<br /><br />Brew
 

Brew2

Chief Petty Officer
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Jan 12, 2004
Messages
427
Re: Overheat alarm test

OK...found the connector, turned ignition key to "on", grouned the wire to the block, and got absolutely nothing, no horn, no nothing.<br /><br />So...does this mean my warning horn is kaput or is there a fuse or something somewhere along the line I should be checking?<br /><br />Thanks,<br /><br />Brew
 

dcolpitts

Petty Officer 2nd Class
Joined
Jun 27, 2003
Messages
149
Re: Overheat alarm test

brew2, you should have 2 temp sensors, one one each head. try both, when grounding them out you want to ground the harness side of the connector not the sensor side. I have same yr and hp and had to change the horn last year. post back let us khow what you find out.
 

Brew2

Chief Petty Officer
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Jan 12, 2004
Messages
427
Re: Overheat alarm test

Hey Okam,<br /><br />Tried both of them and got nothting. Guess I need a new horn.<br /><br />Brew
 

dcolpitts

Petty Officer 2nd Class
Joined
Jun 27, 2003
Messages
149
Re: Overheat alarm test

Brew2, I replaced mine with a piazo horn from radio shack with a red led light. I used the purple for + and the brown for ground, mounted it on the console. It works fine for the temp and vro alarms. I added a second buzzer and light for the low oil alarm on the oil tank. The buzzers can be wired for solid horn or beeping. If you want I can email the part #s and diagram if you so inclined.
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Overheat alarm test

Brew, are you grounding the wire from the sensor or the wire going into the harness?
 

CaptainPuget

Petty Officer 2nd Class
Joined
Sep 29, 2002
Messages
137
Re: Overheat alarm test

You should be able to test the horn by sticking a second key in the slot under the neutral throttle lever. If it doesn’t sound off it could be the wiring inside the control box.
 

Brew2

Chief Petty Officer
Joined
Jan 12, 2004
Messages
427
Re: Overheat alarm test

Okam...sounds interesting...I'd probably just replace the horn with an OEM part, but you've now got me curious....if you get a chance I would like to see the diagram/# number...my email is dsample@telus.net<br /><br />Dhadley...I'm grounding the wire going into the harness...I assume this is correct as the wire going into the sensor wouldn't go anywhere but the sensor...correct? By the way, called Jeff at Flagship re the tubes for my carbs...he tracked me down a set...my parents are vacationing near Port Charlotte next week, so they are going to pop in and pick them up...thanks for recommending Jeff.<br /><br />CaptainPuget...I'll check that out...never noticed a slot under there before...thanks.<br /><br />Cheers,<br /><br />Brew
 

Dhadley

Supreme Mariner
Joined
Feb 4, 2001
Messages
16,978
Re: Overheat alarm test

Glad that worked out on the tubes! Thanks for the update.<br /><br />BTW -- vacationing here? There aint a whole lot left!
 
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