Navman FISH 4500, Installation And Operation Manual

This troubleshooting guide is written with the as-
sumption that the user has read and understood 
the relevant sections in this manual.

It is possible in many cases to solve difficulties 
without having to send the display unit back to 
the manufacturer for repair. Please follow this 
troubleshooting section before contacting the 
nearest Navman dealer.

There are no user serviceable parts. Specialized 
methods and testing equipment are required to 
ensure that the display unit is reassembled cor-
rectly and is waterproof. Users who service the 
product themselves will void the warranty.

Repairs to the product may only be carried out 
by a service centre approved by Navman. If the 
product must be sent into a service centre for 
repair, it is essential to send in the transducer(s) 
at the same time.

More information can be found on our Website: 
www.navman.com.

1.  The fishfinder won’t turn on:

a)  The FISH 4500/4600 is designed to operate 

on a 12/24 volt battery system, where the 
voltage may vary from 10 to 35 volts. If an 
excessive voltage is supplied, a fuse will be 
tripped, turning the display unit off. Check 
the fuse.

b)  Check that the power cable connector at the 

back of the display unit is securely plugged 
in and the collar is locked in place. The collar 
must be secure for watertight connection.

c)  Measure the battery voltage while the battery 

is under load - turn on some lights, radio or 
other electrical equipment connected to the 
battery. If the voltage is less than 10 volts: 
- 

the battery terminals or wiring on the 
terminals may be corroded.

-  the battery may not be charging cor-

rectly or may need replacing.

d)  Inspect the power cable from end to end 

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

e)  Ensure that the red wire is connected to the 

positive battery terminal and the black wire 
to the negative battery terminal. If wired for 
the Auto Power option, ensure the yellow wire 
is connected to the ignition circuit. Also check 
the boat’s main switch circuit (see section 6-5 
Wiring options).

Appendix C - Troubleshooting

f)  Check for corrosion on the power cable 

connector and clean or replace if required.

g)  Check fuses that are placed in line with the 

power cable. A fuse can be blown despite 
appearing to be good or the fuse may be cor-
roded. Test the fuse or replace it with a fuse 
known to be good.

2.  The fishfinder won’t turn off:

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 op-
tions.)

3.  The fishfinder operates erratically:

a)  Check that the transducer does not have de-

bris (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 posi-
tion. (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 bub-
bles 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 

FISH 4500/4600 

Installation and Operation Manual

34

NAVMAN