Sonar Shuts Down When Cranking

I replaced my sonar unit up front recently and used the same wiring running back to the auxiliary power panel.  When I crank the big motor, the sonar cuts out.  The old one  didn’t.  The console sonar trips to (low voltage), but my thought is that’s because I have my voltage warning set to 11.5 volts.  Any thoughts on what may be happening?

Most Outboard Motors will start as low as 10V if your Battery has a bad cell, there may be enough juice to start but too low for good electronics.

First step is to clean and tighten terminals at starting battery then use external charger the night before to get battery fully charged. Turn on sonar before starting boat then see if it still happens. 

If its all good, terminals were the problem.

If it still happens, take your battery to auto parts store to be tested.

If it is good but comes back later in the day, have marina check charging system.

I had the same problem, bought a new battery then saw how much corrosion was on the terminals cleaned and charged. All better returned the 100 plus dollar battery.

My brand new boat that I've got last year the electrical guru at boat dealer stuck everything on the accessory side of the starting battery

I don't know if it was a cost savings so didn't have to buy large lug starting connectors

Once I separated the power and ground from the boat motor to the battery proper lugs

Accessories on the accessory side wing nut side of the battery my problems went away and I run two helix locators

I haven't had this problem with my Helix unit.  But I know guys who run Solix units that have this problem.  I talked with a rep once and he said the Solix draws even more power than the Helix.

But yah, the issue is the gauge of wire and the battery.

When I upgraded to the Helix, I also upgraded all of the wiring to make sure this would not be an issue.

Happened to me first time in 20 years the battery was low and would not hold a charge i also bought biggest battery for starting and not a problem since. First I thought it was the helix but when I got no power to start motor I realized the battery was junk. Agm battery what a difference but double the price.

This has happened 2 times in 20 yrs of boating owning 4 different boats.It always turns out that my cranking battery is getting low.I replace it with the largest avail and no more problems.

Yes newer units draw more power.  I always run my units direct to the battery with heavier wire, and install a fuse there.  The wire I use is extension cord that has been cut in 1/2 or had an end go bad etc.

I'm pretty sure it more than likely shuts down because too much draw on the battery. Especially if you have multiple devices running. If your older model didn't do this it could mean that device wasn't drawing as much on the battery. Just a thought....... Good luck fishing.

I have the same problem. Front hummingbird shuts off when I crank up the big motor. I have a new battery and the connections are clean. I have a fuse panel under the dash board and I'm pretty sure the wires to the front sonar are connected to a fuse at the fuse panel. From what I'm reading here I should run heavier gauge wire from there to the front? 

 Thanks, JJ  

Type of sonar is another factor.  The newer ones with down/side imaging take more to run and are more sensitive to low voltage.  My dad had issues with his Humminbird Helix, even when the battery wasn't that low.  His issue turned out to be that the wiring in the boat was not adequate.  Worked fine for his older sonar, but not the new one he bought.  I forget what the old wire was, but I think he replaced it with 12 gauge and had no issues since.  Not sure if he needed 12, but its what he had already laying around.

He actually took it back the first time because he had a fully charged battery and still had issues.  Didn't even need to crank the motor, did it on its own with nothing else running.  When the second one did the same thing, then he asked someone and that ended up being the issue.

That’s another good job on the people of Lake Link. Happens a lot!!! Different fishing techniques are another good thing that happens, or when a guys motor don’t start. Good stuff. I’ve been saying I’m getting a Battery Load tester for ever. I think it would be worth it’s price. Test your friends batteries too.

Glad I can help

But proper wiring on the battery helps a lot

Nice follow up. Makes people want to help and helps others know what worked. 

To come full circle on this one, I changed my terminal connections  to what BA suggested and replaced my 625 cca starting battery to a new 800 and resolved the issue.  Thanks again for the input.

mine did the same thing, took it in and replaced the battery. problem solved. I thought he was nuts, Im always learning

Thanks guys.  Leaning on the battery replacement side even though it’s only three years old because I fish the big lake solo quite a bit.  

I appreciate all the feedback!