engine alarm???

[MIKETTURBO]

hay guys, my 94 jonny 175 has a problem with the alarm going off.sometimes as soon as i turn the key on,hot or cold.steady tone! i ck. all the oil level & fuel. i'm thinking of a short in the control box,i bang on the box & wiggle the wires going into it as well as by the motor.still going off.then it just stops by itself.only happens once in a while.any ideas???

[THEFERMANATOR]

Could be a bad blocking diode at the engine, or a shorted out warning horn.

[ssiredfish]

Is it an Oceanrunner? Only reason I ask is because mine would do the same thing after performing all the checks. One month later I was idling back, not by choice.

Is it doing it when the key is on(not started) also or just when she is started?

[MIKETTURBO]

my experince with diodes are they are either good or bad.my problem is intermittent.Also it comes on sometimes as soon as I turn the key to ign.pos. (cold motor), & stays on when it starts. it'll stop on its own after a while,sometimes while underway it'll come on & off,& it's definitly not overheating.BTW it is an OCEANRUNNER.Its very annoying when you load up & are ready to head out for a nice day of fishing & that damn alarm goes off.

[phatdaddy]

i have a merc, so its an apple to oranges, but have you isolated it to oil sensor or heat sensor. i had a oil alert box go bad and it would do similar things. on mercs an intermittent horn is oil & a single horn is heat.

[THEFERMANATOR]

The blocking diode is there to keep the power pack from tripping the alarm system, and when the blocking diode goes it can cause eratic warning horn operation. Being an OCEAN RUNNER means nothing here as OMC used the same harness and system on ALL engines of each generation. You need to isolate wether it is an overheat, fuel restriction, or oil injection alarm triggerring it. You need to check that the blocking diode is there and working so as to avoid the power pack from inadvertantly triggerring the warning orn or the warning horn triggerring the engine safety system and running at reduced RPM's.

[MIKETTURBO]

thanks for the help guys.a constant alarm is an overheat cond.on a johnson.I can be running at 4000 rpm & it'll go off with no loss of power,just that annoying alarm.then it'll just stop ringing.what makes it so hard to trace is that it won't sound for 3 or 4 days then i;ll go to the marina load up & get ready to start her up & as soon as i turn the key the alarm is supposed to chirp, but it'll stay on constant.i'll shake the key switch,wiggle wires & such,& I before i get a chance to shut off the key, it'll stop. go figure???

[phatdaddy]

do you have a water pressure & temp gauge? if so, disconnect the sending unit for the horn and see if problem goes away. some have sensors on both heads, some on one.

[cterrebonne]

I would test as ferm suggest. find the test procedure on the diode. it is cheaper than possibly buying that expensive warning horn and it not being the issue. i just checked the price p/n 583891 $79.13 wow that's a lot.

[THEFERMANATOR]

If the horn is going off without a loss of power, then it is most likely the fuel restriction sensor or a bad warning horn tripping it. It doesn't take much to set the horn off on the 3 wire ones, so that is why it is crucial that the blocking diode is in and working.

[MIKETTURBO]

thnx guys,I gonna look onto the diode as ferm suggested.The book says fuel restriction will sound at full or near full throttle.I know (ya never know) .

[THEFERMANATOR]

thnx guys,I gonna look onto the diode as ferm suggested.The book says fuel restriction will sound at full or near full throttle.I know (ya never know) .

When there is a fuel restriction, yes it will only sound under hard load. When the sensor fails though it can trip whenever. Also a small even to smal to see spot in teh insulation missing from any of the wires for the warning horn can trip it as well.

[reelapeelin]

Also a small even to smal to see spot in teh insulation missing from any of the wires for the warning horn can trip it as well.

That sounds like nasty business to run down...how best to find this little gremlin?...sounds like something that'd happen to me...:cen: