I’m not sure how to explain this but here is the best I can. I’ve had an HDS9 gen3 at the console and HDS9 gen2 at the bow for a couple of years now with no issues. Recently I changed out the gen3 to an HDS12 gen3. It works fine until I turn on my bow unit. When they are both powered on, the HDS12 “glitches and flickers” the entire time. It happens on chart, sonar, and down/side scan. As soon as the bow unit is off, the HDS12 has no issues. Here is what I’ve tried so far. I’m a novice at all of this electrical mess, but I’m about ready to trade for the HDS9 back!

1) I’ve swapped locations of the graphs and still get the same issue.
2) checked all connections at the battery, disconnected, reconnected, even installed a couple new clips on the wires.


my battery is a Duracell, AGM size 31. Thanks Coach

It's a power issue. The 12 isn't getting enough power. You'll have to run independent power from the 12 straight to the battery. 10 or 12 gauge wire.

Thanks!!! Gonna try that today.

Make sure unit transducers are set on different frequencies.