Vexilar Flasher Family 2013 - Manual (Page 62)

62
ELECTRICAL INTERFERENCE
TROUBLE SHOOTING
There may be situations where you experience interference from other electrical devices,
not just another nearby depth sounder. This interference will show on your display as
random signals which can appear anywhere. They will interfere with your ability to see
the normal display signals. The most common sources of interference are electric trolling
motors and engine ignitions systems. The Interference Rejection feature will not have
much effect on these types of interference, as this feature is designed to only deal with
signals from another sonar device. Here are some things to be aware of when it comes to
electrical interference.
S
ourcES
Interference can be introduced into your sonar system through the power supply,
transducer line, or both. To identify the source, unplug the transducer and run the trolling
motor or the engine. If the interference disappears, you know the noise is coming in
through the transducer line. If not, it’s coming through the power line, or both.
w
IrIng
Power line interference can generally be solved by improvements in the wiring positions,
connections, and grounding. You want to be sure the sonar wiring is as far away as
possible from the trolling motor wiring, and the wiring is neat. Make cable runs as short
as possible and neatly coil extra wire and tie it off so it stays put in rough water or
while pulling the boat. All electrical connections should be in very good condition. Push-
on terminals should be tight. Wire crimp connections should not come free when pulled
firmly. Conductors should be shiny, not dull or corroded.
g
roundIng
The boat’s electrical system should have a common “Earth” ground to the water. Most
boats electrical systems are grounded through the outboard to the water. Many times a
electric trolling motor interference problem can be solved by a “ground” wire from the
negative trolling motor power source to the negative of the starting battery.
E
quIpmEnt
Electric trolling motors and gas engines can have technical problems that can cause
interference. If common wiring improvements do not solve the problem, be sure to check
with the manufacturer to see if there are any recommendations or updates available
regarding interference with depth sounders.
For more information regarding interference issues, check the Support section of the
Vexilar web site or contact our service department.