I recently bought a second Lowrance HDS12 Carbon to have dual graphs on my console. I’m having some issues and I’m not sure if it’s a power supply problem, ethernet cable problem or if the new graph is bad. See pictures attached. The navionics/chart is dropping out where I’m losing my contour. My waypoints and trails don’t drop. My graph on the right is used for structure scan and side imaging. That unit will freeze up at times and won’t respond when you touch the screen or any of the buttons on the right side of the graph. The new unit is on the left side and when I put it in “stand by” it takes itself out on its own. Confused and frustrated. Any help would be appreciated.

This is the screen it goes to when it takes itself out of “stand by”

Swap power cords and see if it still does it. That will eliminate a power supply problem. If its still there then disconnect the ethernet and do the same. If units still doing it then you may have to call Lowrance.

Thank you for the feedback. I have done exactly that and the problem continued. I guess contacting Lowrance is the next step.

If I comprehended his post correctly, he's having issues (though different) with both units. If those units are simply tied into the boat's existing wiring under the console, swapping the two power cords would seem to not help much at all with diagnosis. Both units are flaking out, so you can't say one has a good confirmed power connection.

Easy solution - find someone with working Carbon units; Put yours on their boat, or put theirs on your boat. I'm betting a friend's Carbon will "break" when powered on your boat.

Back to the matter of "testing": If the wiring from the battery to the console is undersize for the load he has, swapping the power cords between units answers no question.

Two Carbon's can pull 4 Amps at 13.8V as typical power according to Lowrance. If he has a weak battery and/or inadequate wiring, the voltage under load will be lower than 13.8V. If the voltage reaching the console drops to 12V, the Amp load will increase to 4.66, as an example.

The failure rate on today's modern marine electronics is quite low (in general for all established brands, no bashing undertaken.) The chance that you would end up with two units that are faulty is nil. What IS very common is crappy installation, especially with respect to power. Any unit will go a bit wacko when the power supply drops out of spec, and you seem to be describing just such a scenario. Have you enabled the voltage reading for the display to see what it says it's getting?

It is rather impossible to diagnose a wide range of flake-out issues like you describe without first confirming good power within specification. I suspect Lowrance won't be able to do much remotely with what you describe, as could no one else, either. Run some 10 gauge marine wire (even temporarily with lids open and wire across the deck) from the battery for both the positive and negative leads to power one unit. Just disconnect the Lowrance power cable under the dash to move to the 10 ga. for dedicated power for one unit. I bet that unit suddenly behaves well. Let me know.

Sorry I didnt read Flippin-outs message, he is spot on..


First thing I would do is connect the units to a seperate battery. Some boats have pretty small wiring from the battery to the panels near the console. If I am correct you are pulling 2amps per unit, might need to clean up some wiring which is dropping the voltage down below recomended values. If you have a volt meter you can check this at the battery, and then near the terminals for the wires that go to the HDS units. I would bet you are running a skosh low, and when you start a pump or start the boat it drops Voltage enough to reset the unit. You can instant message me and I can give you my cell. This is what I do for a living, except it is on manufacturing equipment. But you can simply attach the units to a small 12v sla or agm battery (similar to a battery for a deer feeder) for testing this theory.

Good luck and let me know if I can help.. please let us know what you find.

Prosise

He doesn't even need a voltmeter to see what voltage is present at each display. Lowrance can display the voltage in the data overlay on the screen. That "voltmeter" is almost certainly a standard design embedded into one of the integrated circuits in the unit. Such implementations are typically very accurate. I've even used a set of automotive jumper cables to prove the point to someone swearing their electronics unit was defective.

My installer ran 10ga stranded wire in my boat thinking that was the problem. The problem continued after installing the heavier wire. I will check the voltage displayed on the units and see what it’s reading.

I hope he ran both positive and negative wires to the same battery and did not run the negative to a common ground....also direct to the battery and not thru switches, busses etc.

I would try the other's ideas about running each one straight to a temporary 12v power source to check. Did this problem just start when the second unit was added? If so disconnect one at a time and test each separately. If they work with only one hooked up at a time it is definitely a power/ground.....usually ground....issue.

You've gotten your technical terms confused and incorrectly applied. Just so you know, "common ground" means multiple circuits sharing a negative bus at a zero potential level. Every circuit in the boat (except the trolling motor system) uses "a common ground". A wire run to the battery is still "common ground". An example of a "not" common ground would be if he had a second "house battery" for electronics and the Ground for the electronics on that battery was never in any way connected to the Ground of the first battery. Likewise, it you did tie the two Grounds together from those two house batteries, you WOULD have a "common Ground." I laugh at your suggestion that a bus is a bad idea too. A properly implemented bus is actually a great way to resolve the crappy electrical installation in many boats. Power/Ground? "Ground" is half of any power distribution system, so you repeat yourself? Try "It's usually a power issue" and you'll be saying what has already been said. There is no basis in saying that "it's usually a Ground issue." In 40 years of working on them, I've not seen that to be true, nor does that make any technical sense. Power is a circuit; half of it is positive, and half of it is negative. Excessive resistance in either half (or both in sum) causes too much voltage drop, which is the #1 issue for "bad electronics" in boats - when it's not the electronics at all.

Have you had the battery load tested? A battery with a failing cell will "seem" to have good voltage, but falter rapidly as a load is applied. You never did say if you had any issue with your original unit before adding the second unit. My bet is still on a common fault for both units' misbehavior. You can use a TM battery to test the idea - just move the + and - for the dedicated electronics power to a TM battery. If you borrow a TM battery to test with, remove it's other connections first. Usually not an issue, but if you have a TM with a Ground isolation fuse in the head unit I wouldn't want to make you blow that from connecting something else to that power system.

Never had a problem until the additional unit was added. As a matter of fact, if I turn the new unit off the other two (the original units) work flawlessly.

Disconnect the Ethernet bus connections and boot all 3 up again to see how they act. Have you checked the software version level. It's best to have all units of the same model run the same software version. Companies don't test units in a mixed revision configuration, typically.

Do you have a unit 3 your imply at the bow, or did you replace one at the console. (I'm trying to understand the "original units" comment? When you have the issue, are you just powering two, or all 3? If all 3, the battery load question is still hanging.

If you have an "installer" maybe your or he knows someone with a Carbon 12 or Live 12 that could be used as the "new unit" in a boot up test? This way, you'd get the same system load, but remove that added Carbon to get it.

Could be the Ethernet cable, my cable is wonky and I have to leave it unplugged or it’ll make my graphs do all kinds of odd stuff. I’ll plug it in every now and then for it to add/delete waypoints. Guess I could swap it, but mines a pain to get to.

Agree. An unreliable cable could prompt unpredictable issues. I had suggested he disconnect all units from the network and power them up again.