06/01/2026
If your screen flickers, reboots when you start the big motor, or has massive interference on the sonar—don’t blame the unit yet.
90% of the time, the problem isn’t a broken graph. It’s “Dirty Power.”
When boats are assembled at the factory, the wiring harnesses are designed for basic accessories (lights, bilge pumps, etc.). But today’s high-tech fish finders, live sonar systems, and networking hubs draw serious amps and are incredibly sensitive to voltage drops and electrical noise.
If your electronics are pulling from the factory accessory block, you are setting yourself up for failure. Every time your livewell pump kicks on, your graphs suffer.
Here is the PTG Electronics guide to “Clean Power”:
1 Watch the Daisy-Chaining: While linking a couple of displays together is generally fine, daisy-chaining three or more units at once is where the trouble begins. It highly increases the chance of voltage drops and makes it incredibly difficult to troubleshoot the exact cause of an issue.
2 Run Dedicated Power: You need a dedicated, heavy-gauge marine wire (usually 10 or 8 AWG) run directly from your battery to a dedicated electronics fuse block or harness.
3 Isolate the Interference: If you are running forward-facing live sonar, keep those power runs completely isolated from your trolling motor cables to prevent onscreen interference lines.
4 Check Your Voltage: Turn on ALL your pumps, your trolling motor, and your graphs. Look at the voltage overlay on your bow unit. If it’s dipping below 11.5v, you have a power delivery issue that is costing you performance.
Clean power = crisp sonar returns, zero screen flickering, and units that stay on all day.
Save this post for the next time you are troubleshooting your graphs!
Dealing with persistent power issues or planning a new graph setup? Send us a DM or give us a call at PTG Electronics—we’re always happy to share our expertise, talk through your setup, and give you our professional opinion!
