I'd check all wiring connections, even take them apart and redo them if you have too. Could be corrosion where you can't see it.
I have an Eagle and a Humminbird on my boat. They both work great....most of the time.. Then they both mess up and don't read. The display just flashes the depth it stops working and the screen has small vertical lines in it. The Humminbird goes blank on the graph but reads depths of say 100' in 20' water. Then all of a sudden both work again. This happens even when using only one at a time. Please help, this is getting frustrating.
"If people concentrated on the really important things in life, there'd be a shortage of fishing poles." ~Doug Larson
I'd check all wiring connections, even take them apart and redo them if you have too. Could be corrosion where you can't see it.
If you are running the depth finder off the same battery as the big motor, it could be your voltage regulator on the boat is going bad. I had the same problem you are having a few weeks ago. it was the voltage regulator going bad.
listen with your eyes---its the only way to beleive what you hear...
Smitty,If your running at a hi speed when this happens it could be you need hi-speed transducers.I had this problem with my Matrix,screen froze,showing crazy depths[100-200 ft].Might be it,hope ya figure it out.
Good Fishin To Ya!! Dennis Dale Hollow Crappie www.dalehollowcrappie.4t.com
Another possibilty is that you are running both at the same time and they will interfere with each other. I have seen this when someone gets within a short distance of me, or I forget to turn off the dash mount when I go to the bow. I have also seen this when I run through a massive amount of bait fish.
You could also be experiencing some electrical interference. If it is happening when you are running your big motor. It could be the voltage regulator, or, just interference. You might try rerouting your wiring for it away from the big motor wiring. It could also be caused by wiring for bilge, or areator. Also, check your transducers to make sure they are both mounted properly and in a good position. Turbulence while under way will make a finder act very strange.
Reaper, Where Fish come to Fry
This is not when you are in extreme shallow water is it? Mine will
sometimes go crazy when I pull up to the bank or something, have to
shut it off and turn back on again. Probably not, but just a thought.
Shoals Area Crappie Association
mine acted up when running troling motor so i hooked the power to the cranking battery . . have herd of the motor as in the other [post . try a seprate battery .
retired and now i will always fish