Anyone had electrical issues caused by plotter/fish finder ? Dragonfly in particular

[QBhoy]

After spending an age trying to track down electrical shorting or earthing issues all around the boat and engine too…I am 99% certain that it was all caused by the dragonfly unit. In particular from the harness loom from transducer/power supply that plugs into the back of the unit.

 

[dingbat]

After spending an age trying to track down electrical shorting or earthing issues all around the boat and engine too…I am 99% certain that it was all caused by the dragonfly unit. In particular from the harness loom from transducer/power supply that plugs into the back of the unit.

What is going on?

Pulse generator, communications inputs (NMEA) and input power are isolated internally from each other. The only thing in common is ground.

 

[QBhoy]

What is going on?

Pulse generator, communications inputs (NMEA) and input power are isolated internally from each other. The only thing in common is ground.

Yeah. It’s through the ground. No nmea available in those units. Read online that there may be known issue with the wiring harness since posting

 

[dingbat]

Read online that there may be known issue with the wiring harness since posting

Looking at the wiring diagram, the harness is wired 1:1. Pretty hard to screw that one up.

Pin 4 12VDC
Pin 5 GRN
Pins 1 & 8 are transducer Drive and Return
Pin 10 ties transducer shields (pin 1 & 8) to drain

The harness has two drain (shields) lines (24 awg) and an earth ground (20awg). Where did you tie the “drain” line too?

You’ll have issues if ground and drain are not at the same potential.

 

[Grub54891]

try putting a ferrite on the power wire.

 

[QBhoy]

try putting a ferrite on the power wire.

Sounds a good idea.

 

[QBhoy]

try putting a ferrite on the power wire.

Looking at the wiring diagram, the harness is wired 1:1. Pretty hard to screw that one up.

Pin 4 12VDC
Pin 5 GRN
Pins 1 & 8 are transducer Drive and Return
Pin 10 ties transducer shields (pin 1 & 8) to drain

The harness has two drain (shields) lines (24 awg) and an earth ground (20awg). Where did you tie the “drain” line too?

You’ll have issues if ground and drain are not at the same potential.

Thanks for looking into that. Appreciate it. Yeah, you’d think it would be no problem. But definitely found issue with its cable harness and or connector. Problem has completely gone after removing it all.