Navman 4432 Manuel D’Utilisation

 

The fishfinder may have been wired for 
Auto power. In this case, the fishfinder 
cannot be turned off while the ignition 
power is on. (See Auto power wiring in 
section 6-5 Wiring options.)

a)  Check that the transducer does not have 

debris (e.g. weed, plastic bag) caught 
around it.

b)  The transducer may have been damaged 

during launching, running aground or while 
underway with debris etc. If the transducer 
has been impacted, it may have been kicked 
up on the bracket. If it is not physically 
damaged, reset the transducer back to 
its original position. (See the Transom 
Transducer Installation Guide.)

c)  When the transducer is less that 2 ft. (0.6 m) 

from the bottom, the depth readings may 
become inconsistent and erratic.

d)  Manual Gain may be set too low, which may 

cause weak bottom echo or no fish signals. If 
in Manual Gain, try increasing the Gain.

e)  Ensure the back of the bottom surface of 

the transducer is slightly lower than the 
front and the front is as deep in the water as 
possible in order to minimize the generation 
of bubbles through cavitation. (See the 
Transom Transducers Installation Guide.)

f)  Check the transducer and power cable 

connectors at the back of the display unit 
are securely plugged in and the collars are 
locked in place. The collars must be secure 
for watertight connection.

g)  Inspect the power cable from end to end 

for damage such as cuts, breaks, squashed 
or trapped sections.

h)  Ensure there is not another fishfinder 

or depth sounder turned on, which may 
interfere with this fishfinder.

i)  Electrical noise from the boat’s engine 

or an accessory may be interfering with 
the transducer(s) and/or the Navman 
fishfinder. This may cause the fishfinder 
to automatically decrease the Gain unless 
using Manual Gain.

 

The fishfinder thus eliminates weaker 
signals such as fish or even the bottom 

from the display. This may be checked 
by switching off other instruments, 
accessories (e.g. bilge pump) and the motor 
until the offending device is located. To 
stop problems from electrical noise, try:

- 

re-routing the power and transducer 
cable(s) away from the boat’s other 
electrical wiring.

- 

routing the display unit’s power cable 
directly to the battery with an in-line 
fuse.

a)  The fishfinder may have Manual Range 

selected and the depth may be outside the 
range value selected. Either change the 
fishfinder to Auto Range or select another 
depth range (see section 4-5 Range).

b)  The depth may be outside the fishfinder’s 

range. While in Auto Range, the display unit 
will display “--.-” to indicate that there is no 
bottom detected. A display of the bottom 
should reappear when in shallower water.

 

The fishfinder may have Manual Range 
selected and the selected Range value is 
too high for the depth. Either change the 
fishfinder to Auto Range or select another 
depth range (see section 4-5 Range).

a)  Ensure the back of the bottom surface 

of the transducer is slightly lower than 
the front and the front is as deep in the 
water as possible in order to minimise the 
generation of bubbles through cavitation. 
(See the Transom Transducers Installation 
Guide, for more information.)

b)  The transducer may be in turbulent water. 

Air bubbles in the water disrupt the echoes 
returned, interfering with the fishfinder’s 
ability to find the bottom or other targets. 
This often happens when the boat is 
reversed. The transducer must be mounted 
in a smooth flow of water in order for the 
fishfinder to work at all boat speeds.

c)  Electrical noise from the boat’s motor can 

interfere with the fishfinder. Try some 
suppression spark plugs.

FISH 4432/4433 Installation and Operation Manual

36

NAVMAN