Warning Horn Activates (No Power Loss); Battery Will Not Hold Charge - Mercury 225 Manual

• The oil level in the engine‑mounted oil reservoir tank is
low. Refill the reservoir tank and the remote oil tank.
Refer to Fuel and Oil for details.
• Battery voltage is out of limits.
• Throttle position sensor failure.
• Continuous horn sound:
• The oil level in the engine‑mounted oil reservoir tank is
critically low. Refill the reservoir tank and the remote oil
tank. Refer to Fuel and Oil for details.
• The oil pump has failed, halting the oil supply to the
engine.
• Engine speed exceeds the maximum‑allowable RPM.
The system limits the engine to within the allowable
range. If the overspeed condition continues, Guardian
places the engine into power reduction. Overspeed may
be caused by incorrect propeller pitch, engine height, trim
angle, etc.
• High engine temperature or low block water pressure.
• Cooling system clogged.
• Incorrect transom height (water pickups not getting
adequate water supply).

Warning Horn Activates (No Power Loss)

POSSIBLE CAUSES
• Warning horn activates on start up. This is normal operation.
• Water is detected in the water‑separating fuel filter. Refer to
Maintenance for procedures on removing water from the
filter.

Battery Will Not Hold Charge

POSSIBLE CAUSES
• Battery connections are loose or corroded.
• Low electrolyte level in battery.
• Worn out or inefficient battery.
• Excessive use of electrical accessories.
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TROUBLESHOOTING
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