Yamaha False Alarm Buzzer Troubleshooting

fishbonesc

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Joined
Apr 16, 2012
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2
Hello, I have a 93' Yamaha 130 outboard and I believe I am having a false alarm issue.

I am having the following problem: As soon as I crank up my engine, cold or warm, an alarm goes off immediately when I turn the key.

My understanding of Yamaha alarms is that alarms are triggered when the thermo or oil sensor switches create continuity between a ground and the alarm wire.

This is some more background information:
  • Oil injection on this motor has long ago been disabled
  • I still checked continuity on the oil sensor float switch in the down, middle, and up positions and only the down position causes continuity from ground to the alarm wire as expected. Float switch is tie-wrapped in the up position causing continuity from white to black, as expected.
  • I unplugged the blue/red striped wire from the oil sensor harness to break any possible continuity and I still get the alarm
  • I replaced the water pump and both thermostats
  • I tested continuity on my temperature sensors in a pan of boiling water and they only provide continuity at ~190 degrees as expected
  • I'm confident that the motor is not overheating, so I unplugged both the temperature sensors and the alarm still triggers.
  • I'm using a standard Yamaha key switch, standard control box (704), and a yamaha multifunction tach. All harneses are plugged together correctly between dash and motor as far as I can tell.


At this point I am very stumped. Even with no continuity from temperature sensors nor oil sensor, I still get an alarm immediately when I turn they key.

Could I have a bad main harness? Are there any other troubleshooting tests I can do? Are there any other ways to figure out what's causing a ground somewhere in my system?

Thank you sincerely for any help!
 

fishbonesc

Recruit
Joined
Apr 16, 2012
Messages
2
Re: Yamaha False Alarm Buzzer Troubleshooting

Since I exausted all possibilities of overheat and oil alams, I decided to order a new Key Switch Panel (P/N 704-82570-08-00) and a new wiring harness (P/N 688-8258A-50-00).

The new Key Switch Panel resolved my problem and I didn't end up using the new main wiring harness. As soon as I plugged in the new key switch to the existing harness, I tested and my alarm problem went away.
 
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