www.iFourWinns.com

Hi Guys,

I've been having this alarm go off at certain engine speeds. It's periodic and seems to depend on the RPM (or vibration) of the engine.

I'm almost 100% certain it's a ground at this point, as I've already:
- Double and triple checked all fluid levels
- Found a disabled Oil Pressure Sending Unit, and Temp Sending Unit. Replaced Both
- Disconnected the Engine Lube Sensor and ran the boat. Still got the alarms.

Since chasing a ground could take years, was wondering whether anyone else has experienced this or knows the usual suspects when it comes to this issue. I've heard the 50amp breaker on the engine isn't the greatest in my year of boat and that it's been redesigned. Would rather not spend $1000's on throwing parts at it if I can avoid that method of repair.

Thanks,

Russ

What you need to do is study the engine wiring schematic (I'm assuming this is a Merc) and see if there are grounds anywhere in that harness. Also make sure that your main power connections (battery cables, starter solenoid connections, engine fm ground cable) are clean, tight and free of any corrosion.
Sounds like you need a Merc factory shop manual to learn how that system works and how to troubleshoot it. What signal is triggering the alarm and why does it occur (ie the alarm for oil pressure or engine temp is related to a certain ohm reading from either sending unit why is that happening? Are the units properly grounded?)...
I might keep a meter in the boat and mesasure the resistance against what the book says when you get the alarm. Are you using Teflon tape when installing them? How did they get "disabled", these sensors rarely fail.

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88 Four Winns 200 Horizon
4.3 OMC Cobra-4bbl
2002 Walker Bay 10/2012 Suzuki 2.5
2008 Walker Bay 8

1998 Jeep Grand Cherokee 4.0/Selectrac
2007 Jeep Grand Cherokee 5.7 Hemi/Quadradrive II

Put you boat/engine info in your signature line.

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1996 205 Sundowner DLX
5.0FL Volvo SX Cobra
Tow Veh: 2012 Nissan Frontier Pro-4X