Fish Finder User's Manual

7. My unit loses power at high speeds.
Your PiranhaMAX™ has over-voltage protection that turns the unit off when
input voltage exceeds 20 VDC. Some outboard motors do not effectively
regulate the power output of the engine’s alternator and can produce voltage
in excess of 20 Volts when running at high RPMs.
8. The display begins to fade out. Images are not as sharp as normal.
Check the input voltage. The PiranhaMAX™ will not operate on input voltages
below 10 VDC.
9. The display shows many black dots at high speeds and high
sensitivity settings.
You are seeing noise or interference caused by one of several sources. Noise
can be caused by electronic devices. Turn off any nearby electronics and see
if the problem goes away. Noise can also be caused by the engine. If engine
noise is causing the interference, the problem will intensify at higher RPMs.
Increase the engine speed with the boat stationary to isolate this cause.
Propeller cavitation can also appear as noise on the display. If the transducer
is mounted too close to the propeller, the turbulence generated can interfere
with the sonar signal. Make sure that the transducer is mounted at least 15"
(380 mm) from the propeller.
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