you can try hooking the bow unit up to the fuse panel, if you get interference, THEN run some seperate/new power/grd wires. I was able to run seperate power wires from the cranking batt to the bow under the floor on my Tracker PT175 w/o much trouble but you may have troubles as you've indicated. I have my HDS 8 wired into the fuse panel at the console, it stays on the entire time I'm on the water, and does not blink or go goofy when I crank up the 60hp. My cranking battery is 4 or 5 yrs old as well.