Garmin Fishfinder 320C Owner's Manual And Reference Manual

Also see for Fishfinder 320C: Template manual Specifications Specifications

7Testing the InstallationWhile it is possible to perform some checks with the boat trailered, the boat should be in the water toproperly test the sonar portion of the installation.Press the POWER/BACKLIGHT key (see pg. 8) and the Fishfinder 320C should power on. If the unitfails to power on, verify that the wiring adapter is seated properly in the back of the unit, the Red and Blackwires are connected to the correct polarity, and that the 2-Amp fuse is installed and not blown. If the unit isconnected to a power supply that exceeds 35v DC, a “Battery Voltage High” warning will be displayed andthe unit will turn off. If the unit does not detect a transducer, it will automatically enter Simulator Mode.When the unit detects a transducer on initial power up, a “Please set up transducer” message willappear. Press the ENTER key (see pg. 8) to select the transducer type. Highlight your transducer type withthe ARROW KEYPAD and press ENTER. Press QUIT to return to the Sonar display.Since water is necessary to carry the sounder’s sonar signal, the transducer must be in the water to workproperly. It is not possible to get a depth/distance reading when out of the water. As the unit powers on, itshould immediately start showing the bottom. Verify that the unit is not in the simulator mode. If the unitis in the simulator mode, make sure that the transducer is connected properly to the unit. When you placeyour boat in the water CHECK FOR LEAKS around any screw holes that have been added below the waterline. DO NOT leave your boat in the water for an extended period of time without checking for leaks.Begin testing the installation at a slow speed. If the sonar appears to be working properly, graduallyincrease the boat’s speed while observing the sonar’s operation. If the sonar signal suddenly is lost or thebottom return is severely degraded, note the speed at which this occurs. Return the boat to the speed thesignal was lost. Make moderate turns in both directions and see if the signal improves. If the signal strengthimproves while turning, adjust the transducer so that it extends another 1/8" below the transom of the boat.It may take several adjustments to eliminate the degradation. If the signal does not improve, it may be neces-sary to move the transducer to a different location.NOTE: When adjusting the depth of the transducer, make the adjustments in small incre-ments. Placing the transducer too deep can adversely affect the boat’s performance and putthe transducer at greater risk of striking underwater objects.)InstallationTesting the Installation