melted Warning Horn

[ljrichey]

bought a boat 89 cajun with a 175 hp johnson gt about a year ago or so---the boat had a cylinder down that was repaired with a piston& rings on only that cylinder--- boat runs fine--- compression on all cyls right at 100 cold---question i know the horn is bad but should i have a volt spike to horn when key is first turned on--- disconnected horn and hooked up dvm to horn leads--12vdc constant---started isolation at temp sensors in heads--moved to vro pump connector--then to float in tank ---still with 12 vdc at horn connection switch on--i know some of this safety runs thru the power pack but it is new to the engine---the horn melt down could have occured when engine went down but i dont understand why i cant isolate the voltage to horn--i must be missing something here-- thats why i ask the experts

 

[glenn property of pam]

Re: melted Warning Horn

this may sound weird but put a light bulb or some kind of load on the horn lead instead of the volt meter and see if it has amps as well as volts. dvm can pick up voltage that bleeds from solid state devices so it shows voltage but at suck a tiny amount of ampage that under load its zero. if it is true volt/amps then one of the safety switchs or the wire itself is playing up. try finding the wire from the motor end and disconnecting it to see if the problem is in the wiring (melted horn kinda indicates a fuse that didnt blow so that could have caused the wire to get hot and melt to another wire) you sound like you understand wiring and stuff so im sure you will chase it down

 

[ljrichey]

Re: melted Warning Horn

i think i read somewhere on this forum that the powerpack sorts out the warning signal and then sends a signal to horn for seconds delay to a constant horn but have different voltages applied to the horn---you may be on to something here about load--just didnt want to spend money on a new horn to watch it go up in smoke

 

[Sureshot]

Re: melted Warning Horn

You should have 12v constant to the horn with the key in on position. How do you know if the horn is bad? Have you tried grounding it out? You should be able to ground the tan wire connected to the horn and get a constant beep.

 

[boobie]

Re: melted Warning Horn

Model # of the mtr ???

 

[ljrichey]

Re: melted Warning Horn

the copper windings internal look to have been really hot ---hot enough to melt the black resin around and on the back side of the horn---Boobie--mtr 89 jonnie J175stlceb

 

[seahorse5]

Re: melted Warning Horn

With the key ON, there is a constant 12 volts to the horn and the warning system. Anything that will ground out a tan wire will complete the circuit and sound the horn. If the horn is melted, then someone kept running the boat while the warning horn stayed on. Just like your car horn, they are not made to be on continuously, only intermittently.