1997 Ranger 692VS
2014 Mercury 175 Pro XS 2B111166
There is a tendency to have interference on the screen when your power is coming from trolling motor batteries. Plus as your trolling motor battery gets weaker throughout the day you lose voltage to the graph. The cranking battery gets some replenishment with power as you crank the motor and move from spot to spot. Even doing that it is still a good practice to charge your cranking battery as well as your trolling motor batteries every time you use the boat.
The best method so there is little or no interference is to wire directly to the cranking battery. When doing this you want a fusible link just a few inches away from the cranking battery on the hot wire. If you pick up power at a distribution panel or a rocker switch you run the possibility of interference, hence the reason its a good practice to isolate graphs to their own dedicated run.
hook a voltmeter to the cranking battery and watch voltage while at higher rpm
2011 Ranger z521/2023 250ProXS
Thanks for all of your input and suggestions. I've been out of the loop for a while. It may be worth mentioning that I switched to Raymarine graphs a year or so ago after my Hummingbird died then my boat was down for a while with engine issues. I never had this issue with the Hummingbird. I couldn't find any over voltage alarm or settings so I called Raymarine and the guy told me that there wasn't a setting and that is sounded like and issue with something on my boat. I'm going to go ahead and run all new wire as soon as I get a chance. And in regard to the comment about the fuse link location, mine is located near the console so I'll install a new one close to the cranking battery. I'll report back when I'm done. Thanks again..
Just wanted to give a quick update on this issue. I FINALLY got time to work on my boat last weekend. Swapped out the rectifier Saturday and spent all day Monday on the lake. Looks like that did it. Graphs didn't shut down all day Also, my tach seems to be working right when before it was jump around erratically, it's now pretty steady. Anyway, thanks again to everyone for helping me figure this thing out!
Thanks for the update
2022 Ranger Z520R, 2022 Mercury 250 ProXS 4s
Dual 16” Lowrance Live’s at console, 12” Live with Active Target, Garmin 8612 and Livescope, and Humminbird 12” Mega 360 at the bow
Lowrance Ghost TM