strange chattering from warning horn when operating trim on 50 merc

[busterandbelle]

first let me start by saying that i am automation and controls electrician so i should be able to get this with some help from you guys. here is my engine info:<br /><br />1993 50hp merc<br />power trim<br />variable ratio oil injection<br />sn# od195683<br />bought new in 96 from plano marine.<br /> <br />on a side note check this out!!!!<br />i bought the moter in 96 under the <br />assumption that it was a 95. my sales<br /> reciept even says 95 merc 50 and has<br /> the serial no and eveything. i just<br /> found out i was misinformed by the<br /> dealer and that my moter is really<br /> a 93(i got this info straight from<br /> mercury marine) thatsa trip,,, huh.<br /><br />but anyway, back to my problem.it started<br />making a funny chatteding noise from the warning horn<br />when i operate the trim motor and the outboard is running<br />(dont make the sound if its not running)<br />i checked the high temp sensor by grounding the tan/blue<br />like the shop manual says and it souds the horn as the book says it should<br />then i checked the low oil sending unit with an ohm-meter(fluke 23)<br />and it shows no continuity like the book says it <br />should. the next step the book says is to replace<br />the warning module. the truobleshooting guide in the book doesnt list the <br />exact problem im having, so i thought id run this<br />by you guys before going out and buying this module.<br />if anyone has any input on this matter i would certainly like to thank you in advance<br />for shariring your skills,, bryan<br /><br />ps: any idea how much this little puppy is gonna cost me?

 

[busterandbelle]

Re: strange chattering from warning horn when operating trim on 50 merc

ANY HELP ?????

 

[sirlespat]

Re: strange chattering from warning horn when operating trim on 50 merc

If problem is only on trim try a couple of things to sort out its origin.<br /><br />1 does it occur all the time trim pump is operating. I check adequate battery voltage loose connectionsnetc<br /><br />2 does it chatter a specific points as the motor raises. I'd look for a broken wire or corroded connection<br /><br />trim pump is probably second highest current draw after starter motor.<br /><br />Bet it is pretty simple when you find it<br /><br />last thought if it is when switch operated is there a intermittant short between horn and trim switch or is some of the return current flowing through the horn somehow (check voltabe between battery+ and motor + then battery- and motor- while operating.probably should only be 0.5V difference)<br />check clean earths they can even rust in the middle of the plastic coating<br />bet you find it in 1 day