Lowrance radar overlay problem

bpsuls

Active Member
Not sure anyone can help me with this but i'll try to explain my problem best i can.

I recently bought a HDS7 gen3 and Point 1 antenna. I have been trying to set it up to overlay the radar on the map but i constantly get a "radar overlay invalid" message on the screen when i am on the water. I have been in contact with tech support, and have tried everything they suggested which ill mention here:

1.Thought it might be a defective point 1 antenna but i got another one and it still does it

2.Thought it might be the new Gen3 unit. I dont think it is because i tried swapping out my Gen3 unit with a older Gen1 hds 5 that i use at the back helm, but it does it too when it is mounted where the gen3 is (front helm)

3. I have a front and rear helm. the front has the gen 3, and has a 2 foot cable to the NMEA T connector. The rear helm has a 15 foot cable to the T connector. If the front one is disconnected and the rear is connected, the Radar overlay DOES work. If it reconnect the front, it stops working. does not matter what unit is connected to it.

I thought it might be the cable on the front one, or the T. so i changed both the T and the cable, but it still does it. I tried moving Tees around, makes no difference.

4. The radar overlay works just fine on the trailer in the driveway all day long. As soon as I am on the water, even just at the dock, it stops working immediately. always works on the trailer, never on the water.

The point 1 heading sensor works good and the GPS on it is always working. i got a 5% on the magnetic field calculation on it, and it has calibrated properly.

I am totally at a loss here. it makes no sense to me why it works on the back but not the front and why it works fine on the trailer but never on the water. short of changing my entire NEMA2K wiring for the whole boat, is there any other reason it would do this? What a nightmare. I would have hoped that $3000 of electronics would be a little more turn-key than this. Its really fizzled the excitement of new toys.
 
Go into the settings menu on the Gen 3. Select Network. Go into the sources menu... under heading select “Point 1.” Does that resolve it? Did you try “Auto Configure” with the NMEA network powered? If not.. NMEA2000 networking error. You should have four tees, two 120 ohm resistors, one on each end of the network backbone. One tee should have power supplied to the network. If the resistance of the network is incorrect, you have more than one power source on the network, or your “drop cables” (connecting devices to the network backbone) are more than 20’ Long, you’ll have issues. Given that it “works on the trailer, but not on the water” look for bad connections...
 
This must be so dissapointing. I was very excited when I added radar, I would have been bummed out had this happened to me.
I think you have a grounding issue, because when you place it in the water she's grounded and something shorts in your front unit, regardless which unit is installed. Do the other functions on the front unit work properly (sonar) or is it just the overlay that isn't working when it's in the water? It all works fine when the front unit is disconnected... That must be where the problem is.
If it's not too much trouble, run a temp power cable from the same bus that the back helm is connected to, to the front and check again when she's in the water.
I'd check the power cables to the front unit, and all wiring from a bus if you have a separate one up front, especially to anything metal in the water, like trim tabs.
You may need to check for stray current when she's in the water. You can google how to do that. Check your zincs too, they'll indicate stray current issues.
 
Thanks for the suggestions. i have a good look at the wiring and checked a few for resistance but i'm basically at the point where i am going to strip everything out and start over. The water grounding it thing is interesting, i agree it must be a ground somewhere. Bait Ban, i have tried to the auto configure as well as selecting the Point 1, no dice. interestingly, when it shows the "radar invalid" problem, i go to the source selector screen, and it shows the Point 1 antenna as selectable for GPS but invalid for heading. then i try to calibrate it, and it says "calibration timed out" instantly. In fact it is so annoying that the only way i actually got to calibrate the damn thing was to go to a parking lot with it on the trailer after hours and did circles in the parking lot, using my tablet in the truck cab to monitor the progress. Just completely rediculous. This is why i swapped out the antenna, because i thought it was that, but it isnt. I am pretty experienced with electronics and this problem just baffles me. you couldn't even make this up. None the less i will check every cable and every Tee one more time for continuity and make sure the resistors have the proper resistance, again.
 
BP, went through exact same issue last season. Check this check that, try this try that. Went in circles for days trying figure it out. End of the day radar dome was hooped.
No idea where you are but you could see if a tech near you could test the dome itself. I know HC can test it.

Pm if you want more info we can chat. Good luck!!
 
Well it just so happens to have been my same problem last year. I spent all last summer dodging land and boaters because my radar wouldn’t work. Talked with both dealer and Lowrance many times and they had no clue other than to say....” have you downloaded the latest update”.... duh!!! Anyways we survived and returned boat to dealer this spring to find out radar dome was scrap. Lowrance supplied a new dome and was installed by dealer. Works great as just fished the north coast for 2 weeks. I wish you luck!
 
My radar works perfect, all the time. its not the radar its the overlay that's the issue. i'm pretty sure its something with the Nema 2K. If it was the Radome why does it work perfectly with the rear station? Only does it when the front station is connected, and yes i did check the little whip that goes to the front station, even bought another brand new Maretron cable for nothing, made no difference. I haven't yet checked the wiring again, which i will do on the weekend. Bait Ban I live in Victoria.
 
When you get it figured out, please let us know what was wrong. This type of problem interests me.
 
I have a similar, but different problem. I have an HDS9 with a 3G radar. The radar works on its own but I can't get the overlay to work. It doesn't seem to "see" the Point 1 antenna, so I can't pick it on the source screen. The point 1 is plugged into the backbone. The odd thing I find is that there is a coiled up NMEA2000 cable plugged into the backbone but doesn't plug into anywhere else (see picture)??!! Not sure if that might need to be plugged into the HDS unit?? It came from the factory this way....
 

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I don't think you can leave any open ended cables like that, i would just get rid of the cable if you don't need it and remove the tee. At least you can diagnose your problem on the trailer! Let me know what you find out though.
 
Bait Ban, is the RI10 module absolutely required for overlay? I've heard that it is and i do not have it. That said, it does not explain why it works fine when just the rear station is connected...
 
So I went out today and finally figured it out!! Turns out I have some sort of ground fault on my nmea 0183. I was chasing the wrong problem the while time (thought it was the nmea 2k network). I still haven't exactly figured out why it does it but I used it perfectly all day once I disconnected my vhf 0183 wire (it's the only device on that network). Started working as soon as I disconnected the radio. Of course now my radio has no position feed so I still need to fix that but at least I know what the problem is. Thanks to everyone for your suggestions though.
 
Bait ban,
My point 1 does not show up as an option on the sources menu. It is obviously plugged in and I assumed it was working but maybe it is using the internal antenna only? If the point 1 isn’t working, could my engine displays (speed, mph, etc) on the evinrude display be using the HD’s internal antenna because they all work fine it seems..?
Could the point 1 be faulty and never worked from the get go?
Thanks
 
Just wanted to add an update on this. As you know i mentioned in my last post that i identified an interference with my NMEA 0183 system. I did a bunch of tinkering with this and found that the actual problem was the 0183 has a bunch of sentences that can be transmitted. By default, Lowrance has heading sentences that it has turned on, and one of them was for heading. I am not entirely sure why that is, but i turned off all sentences other than the ones for the DSC radio receive for GPS location and the ones that the radio sends to the chartplotter to put vessel waypoints on the screen. you can find what these are in your radio manual. Some of you are wondering why this only failed on the water and not in the driveway.... I think it's because it only would do it when the VHF was turned on. I didn't turn it on when it was on the trailer and i was diagnosing, but i did when i was on the water. SOLVED!
 
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