Humminbird 1158c Combo Installation And Operation Manual page 39

7. Test and Finish the Transducer Installation
When you have installed both the control head, the transducer, and accessories and have routed
all the cables, you must perform a final test before locking the transducer in place. Testing should
be performed with the boat in the water, although you can initially confirm basic operation with
the boat out of the water.
1. Press the POWER/LIGHT key once to turn on the control head. There will be an audible
chirp when the key is pressed correctly. If the unit does not power-up, make sure that
the connector holder is fully seated and that power is available.
2. If all connections are correct and power is available, the control head will enter Normal
operation. If no transducer is detected (or one is not connected), the unit will go into
Simulator mode and will indicate this by displaying the word Simulator on the control
head display.
NOTE: The transducer must be submerged in water for reliable transducer detection.
3. If the bottom is visible on-screen with a digital depth readout, the unit is working
properly. Make sure that the boat is in water greater than 2 ft (.6 m) but less than the
depth capability of the unit, and that the transducer is fully submerged, since the sonar
signal cannot pass through air.
4. If the unit is working properly, gradually increase the boat speed to test high-speed
performance. If the unit functions well at low speeds but begins to skip or miss the
bottom at higher speeds, the transducer requires adjustment. Angling the rear of the
transducer downward and/or lowering the transducer farther into the water will help
achieve depth readings at high speeds. If the left side of the fish arch is longer than the
right side, then the back of the transducer is angled too far downward. If the right side
of the fish arch is longer than the left side, then the back of the transducer is angled
too far upwards.
NOTE: Due to the wide variety of boat hulls, it may not always be possible to get symmetrical fish arches
and high speed depth readings at the same time.
NOTE: It is often necessary to make several incremental transducer adjustments before optimum high
speed performance is achieved.
Once you have reached a consistently good sonar signal at the desired speeds, you are ready to
lock down the transducer settings.
5. Mark the transducer bracket location on the transom with a pencil, then pop up the
bracket to reveal the mounting screws. Tighten the stainless steel mounting bracket
screws to secure in place. Hand-tighten only!
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Transom Mount - Side Imaging®