Screen goes blank

My new 798 is working great until i turn on my interior light switch on my lund pro-v. Then my sonar seems like it’s not getting power as the screen gets squiggly lines. It seems like a short somewhere but I’m not sure where to begin. any thoughts?

Are you pulling power from the same circuit as the interior lights? If you are, I’d start by running a new and dedicated set of wires directly to your battery to power your electronics. I bet this will solve the issue. Now if you prefer to have everything on a master switch (I don’t, I like to be able to run my electronics with all the power off everywhere else in the boat so I avoid routing through the master fuse panel) you will need to find an open spot on the fuse panel but most boats leave plenty of open spots for this type of addition so it shouldn’t be an issue.

Hi,
The input voltage to the “H” unit can be easily determined by selecting the “System Status” prompt on Power Up. The sequence to follow is: turn on the unit; hit the Menu button when prompt to select “Menu” comes up on the screen; scroll down to the “System Status” line and select. Scroll thru the three views using the “View” button. The “Self Test” screen shows things like the software rev., unit serial number, unit run time, and the input voltage (note: this voltage is 0.1v lower than the true voltage going into the unit (according to the “H” guys). The “Accessory Test” screen shows all the software supported devices of the unit and there “connected” status. The third screen is “GPS Diagnostic” screen.

Note: to get out of this mode you need to power down and start over.

The “H” units seem to be more sensitive to voltage inputs than the other guys. If you have a weak starter battery (assuming that’s where the electronics are connected >>> YOU NEVER CONNECT ELECTRONICS TO YOUR TROLLING MOTOR BATTERIES), you could see issues on startup. Long runs of small gauge wiring or voltage drops thru connections can explain strange (voltage) values at the unit.

Take care,
Roger

I run my interior lights and power to my hb on the same line. When the little guys gets in the boat he plays with the switches and this turns off the hb. It happens because the voltage goes below a certain point and they are programmed to shut off. Follow the instructions James gave and you will be good to go. I just haven’t run a direct line for mine yet because I rarely use my interior lights so it is normally not a problem.