over heat buzzer

oogaboga

Petty Officer 3rd Class
Joined
Jul 3, 2003
Messages
82
1991-150hp us marine force -when I turn key on buzzer starts and will remain on till I turn off key .is braker bad or what ,it was unpluged when I got the boat but pluged it in and now buzzez all the time
 

12Footer

Fleet Admiral
Joined
Mar 25, 2001
Messages
8,217
Re: over heat buzzer

it sounds like a defctive sender. This could be the breaker you described?<br /><br />Look on the back of the block for a one-wire sending unit. pull the wire off, and check the resitance between the ternimal and the motor frame. If there is continuity, replace the sender. If not, you have overheat problems, or a short in the wire harness to alarm buzzer to ground.
 

oogaboga

Petty Officer 3rd Class
Joined
Jul 3, 2003
Messages
82
Re: over heat buzzer

thanks I'll check it out when it cools down outside
 

oogaboga

Petty Officer 3rd Class
Joined
Jul 3, 2003
Messages
82
Re: over heat buzzer

12footer all I have is a ohms meter were do I set it to check continuity :confused:
 

SlowlySinking

Master Chief Petty Officer
Joined
Oct 31, 2002
Messages
897
Re: over heat buzzer

12footer, let me jump in here and help out. august, first remove the wire from the temp sending unit and keep it away from the block, turn the ignition ON, if the buzzer sounds you have a short in the wiring from the ignition switch to the engine, if not then follow along, set the ohm meter to the lowest ohms scale, probably RX1 if it's a meter with a needle, or to lowest ohm scale on a digital meter, likely 200 ohms, now touch the two meter test leads together and you will see near zero with the needle scale or near 000 with the digital meter, this is the same as having continuity or checking across a switch that is turned ON, then untouch the meter leads and see what the meter reads, this is the same as no continuity or a switch that is OFF. Now connect the test leads to the sending unit threaded post and a bare spot on the engine block, if it reads near zero ohms the sending unit is bad and this is why the buzzer is always on. The temp sending unit for a buzzer system is really just an ON switch (engine is overheating) or OFF switch (engine temp is okay). Hope this is clear (yeah right) <br />and helps you. ;)
 
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