Lowrance power issues

Now that I have the networking problem figured out….when I have two Lowrance units on at the same time in my boat, they flash. It’s highly annoying. Very much so because I have a newer 31 series battery with plenty of power, so I feel they should not be flashing. I turn the brightness down and that helps, but I see other boats with 3 graphs on with no issues. I have nothing else on in the boat either; no pumps, lights, nothing. I have a lead acid starting battery, wondering if I can find a dual purpose out there somewhere, or what are your guys’ suggestions? I don’t have room for, nor do I want to do the 2 battery thing.

When mine flash like that the voltage is around 8-9v. I found a loose connection between my acc switch and the fuse panel. Problem solved.

I always have the voltage up on both of my Lowrance displays. I want to know if the battery is going to die long before it ever does.

What gauge wire to you have feeding the units ? and what is the length of wire as well ?

Using small gauge wire with bad connections can cause a lot of issues. Is your motor running when the screens flash or dose it happen even with the motor shut off ?

I’ll have to look for that connection, see if it’s ok to the fuse panel.

I’m sure it’s not the wire size. I ran thicker than needed wire back to the unit to make sure it wasn’t an issue. The screen flashes a bit less when I have the kicker on, but it still flashes.

I had one of my power plugs to my hds get what looked like a patina of rust on the male pins. Cleaned it up and all was well. I’m not really clear on where the rust came from unless it’s a brass coated steel pins

Definitely turn on the display for voltage. It’s also possible you have a bad battery. Check the voltage at the battery and at the Lowrance plug. The units should run flawlessly at 10.5v or more but you really should be getting 11-12v+ all the time. Anything less could cause a voltage drop if you turn something else on like a livewell pump or lights.

I have a slight voltage drop issue with mine so I usually see around 11.5. Someday I’ll fix it but for now it doesn’t cause me any issues.

I’m starting to think maybe these units are just power hogs. I took the 12 out of my big boat, put it in the little boat yesterday, and it was flashing at me there too. Would be up around 13v while driving, then sitting was all the way down to the 9.5 range. Battery is good too. Kind of a bummer so far.

I wonder if it’s a bad connection between the connector to the graph itself.

How do you disconnect the unit from the power cable to put it on the the other boat? Could you take a pic of the power cable coming out of the back of the graph? I’m wondering if you’ve installed an extra connector or something.

I installed a cheap quick disconnect between the blue connector on my graph and the fuse panel. I did this so that I didn’t have to buy another blue Lowrance power cable to connect it elsewhere. However, I do see about 0.25v voltage drop because of that qd connector.

Unit in question is brand new, less than 10 hrs on it. They have their own power cords in each boat, all are clean and look new as well.

Ok, got it. I’m sort of out of ideas. I just don’t think there’s any way they could draw done a battery that much. Seems like an issue with the unit. The only thing left is to call Lowrance.

I guess the only other thing that remotely makes sense is that the batteries are shot or just not charged. I assume you checked the voltage at the battery when the engine isn’t running?

Voltage can easily run up to 13v when the engine is running even if the batteries are shot or undercharged.

Brian Robinson wrote:

I’m starting to think maybe these units are just power hogs. I took the 12 out of my big boat, put it in the little boat yesterday, and it was flashing at me there too. Would be up around 13v while driving, then sitting was all the way down to the 9.5 range. Battery is good too. Kind of a bummer so far.

I run all day on 2 12’s and 9 no problem. Could probably do 2 days but haven’t tried. So something isn’t right.

Brian,
Sure, sounds to me like you don’t have the proper gauge wire running from your cranking battery to your units. You need to have 10-gauge marine grade wire. Do not run it thru your fuse panel. I set up fuses right at the battery terminal, then run the wiring to your units. Take a look at Sea Clear Power, they have a wiring kit that is awesome. Beats trying to figure it all out yourself, and they have a battery shut off switch. That is what I will be using the next time I rig up a boat. Good luck on solving your problem.

Phillip Ames wrote:

Brian,
Sure, sounds to me like you don’t have the proper gauge wire running from your cranking battery to your units. You need to have 10-gauge marine grade wire. Do not run it thru your fuse panel. I set up fuses right at the battery terminal, then run the wiring to your units. Take a look at Sea Clear Power, they have a wiring kit that is awesome. Beats trying to figure it all out yourself, and they have a battery shut off switch. That is what I will be using the next time I rig up a boat. Good luck on solving your problem.

@fishhog

Not trying to start an argument just a legitimate question. The Lowrance cord has like 16 ga wire for power, why would they require something significantly heavier when they don’t use that gauge to start with?

I understand the voltage drop in 3’ of cable is known but I question the amount of voltage drop over another 3-6’ of the same gauge vs 10 ga.

I have an undesired voltage drop in my setup as well but it doesn’t cause me any issues. It’s only about 0.5V. I may try and see how much of a difference it makes with the way they recommend for comparison. I just struggle to understand the basis for recommendations.

I agree. The wiring will only be as good as the smallest wire in the installation, so running a heavier wire won’t really do anything. That being said, I did run a bit heavier wire, but not much, probably like 14 stranded I think. It’s a solid wiring installation, so I really don’t think that’s it. I’ll be giving it a look thru this winter tho when I tear the back of the Lund apart again for a livewell pump that won’t work and I can’t budge. Good times.