HDS 7 – GPS Won’t lock on Satellites

I have had my HDS 7 and HDS 5 since last year. The HDS 5 is mounted on the bow and the HDS 7 is mounted in the back in the electronics case by the tiller. I have never had a problem with the HDS 7 locking on satellites until today. I installed structure scan recently and this was the first trip out with the structure scan installed and the HDS 7 would not lock on any satellites. The HDS 5 worked just fine.

Did the structure scan affect something with the GPS on the HDS 7 or is this just a coincidence? The structure scan module is mounted right next to the HDS unit. Could that cause this issue? Any help would be greatly appreciated.

Thanks

Mike

If the 2 units are hooked thru the ethernet? connection tell the hds7 to use the hds 5’s antenna if there is a problem with the hds7’s antenna then the 7 will run

The two units are connected so I guess that would work. It is just strange that I have never had any problems until I installed the structure scan. Thanks for the advice.

Probably just a fluke. There are days when satellite signal is just a little weak. Either try whats mentioned above or pull it out of that compartment so it has a direct shot to the sky and see what happens.

I was messing around with it in the garage last night and I pulled the unit out of the electronics compartment as far as my cables would allow and it still wouldn’t work. I moved the HDS 7 unit to the bow and used my HDS 5 power cable and it worked just fine. It is almost like the HDS 7 doesn’t like being that close to the LS1 Structure Scan Module.

Also, for the life of me I could not find an option to set the HDS 7 to use the GPS antenna from the HDS 5.

I would removed the structure scan and see if the problem goes away. If it does, you isolated it and can contact Lowrance and see if there is a known issue with it.

How long have you had it searching for? I’ve had Lowrance units take over 20 minutes to lock on the “first” time, even if I “helped” it by giving it an idea of where exactly I was. Not sure if you did a upgrade recently to the software or something… I’m just saying right about the time it finally came up I was about to start making phone calls to Lowrance, couldn’t believe how long it took.

Edit: after re reading you thread, the above is probably not the issue…

maybe there is a software update you need to do.

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I was messing around with it in the garage last night and I pulled the unit out of the electronics compartment as far as my cables would allow and it still wouldn’t work. I moved the HDS 7 unit to the bow and used my HDS 5 power cable and it worked just fine. It is almost like the HDS 7 doesn’t like being that close to the LS1 Structure Scan Module.

Also, for the life of me I could not find an option to set the HDS 7 to use the GPS antenna from the HDS 5.

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See page 80 of your manual.

Data Sources

An advanced feature that allows you to use
data from a network data source or data from a
sensor connected to your unit.

If, for example, you do not want to use your
unit’s internal GPS antenna, you could use an
external GPS antenna connected to an ethernet
or NMEA 2000 network.

To access the Data Source Selection Screen,
highlight Data Sources on the Network menu
and press enter.

To select a data source:
1. Select a data category (GPS in your case) and press the keypad to the right.
A subcategory list will appear.
2. Select a subcategory and press the keypad to the right. A list of sources will
be displayed.
3. Highlight a desired data source and press enter.

Thanks for the input guys. The software is up to date Nick and and I allowed it to search all day yesterday while I was on the water.

Dandorn I did see this when I was playing around with the unit but I don’t have an external antenna so it wasn’t giving me any options other than the unit itself. I have never had any issues until I installed the structure scan recently. All last year I used the unit with out the structure scan and the unit was mounted in the same spot and I never had any trouble. I did find out I can’t set up my HDS 7 to utilize the HDS 5 antenna unless i set up a NEMA network. Right now the two units are connected via ethernet.

I did unhook ethernet cable running to the HDS 7 from the structure scan module and then the HDS 7 locked onto satellites right away. Apparently there is something wrong with the structure scan.

I would call Lowrance and get their take on it. It may be a case of the structure scan producing interference or something that messes up the ability to acquire satellites. I wouldn’t think so, but stranger things have happened. Lowrance should be able to help you trouble shoot it though.

What software version is in the HDS 7 and 5? There is a 3.5 available thay i believe you need to run LSS

Moreyes – the software is up to date and the structure scan works great. The GPS on the one unit just doesn’t work unless I unhook the ethernet cable running from the HDS 7 to the structure scan module.

John – That is exactly what I was thinking. I will call Lowrance this evening and see what they think.

Thanks for the help guys.

I know when you have ethernet between two units, it will force both units to run off a single transducer. It may do the same thing with the GPS antenna. Just a thought. If the 7 seems to be plotting your trail accurately, but doesn’t show satellites in the status screen, that might be why. If I was home, I would go mess around with mine and see what I could figure out. I have the same setup except I added the LGC-4000 puck this year to get a little better accuracy.
I would still call Lowrance and ask them though.

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I know when you have ethernet between two units, it will force both units to run off a single transducer. It may do the same thing with the GPS antenna. Just a thought. If the 7 seems to be plotting your trail accurately, but doesn’t show satellites in the status screen, that might be why. If I was home, I would go mess around with mine and see what I could figure out. I have the same setup except I added the LGC-4000 puck this year to get a little better accuracy.
I would still call Lowrance and ask them though.

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The 7 is not plotting a trail at all. The triangle representing the current location just shows a question mark and eventually I get a “No fix GPS” alarm.

I may end up adding a puck as well. We will see what Lowrance has to say if I can ever get through to someone. Let me know if you think of anything else. Thanks John.

what happened? why the mess w LSS1?

Stan

No resolution yet. After not being able to get through to Lowrance on the phone I sent them an email 2 days ago but I haven’t heard anything yet.

Just out of curiosity, since you mentioned that the 7 works fine up front with the cable that the 5 usually runs off of, have you tried putting the 5 in back next to the LSS and see if the 5 works back there? I would assume that it would not, but just something to check off.

Have you tried switching the ethernet cords around on the LSS “out” terminals? such as if #1 terminal is now going to the front(hds-5), and the #2 terminal is going to the back(hds-7), switch the ethernet connections around and have #1 terminal hooked up to the back unit etc.

If the 5 doesn’t work in the back, is there anyway to switch the entire ethernet cables around to eliminate a potential bad cable as being the culprit?

I spoke with Lowrance and they said it could very well be interference from the structure scan module. They said they have never encountered this becauase people don’t typically mount the structure scan module that close to the HDS unit.

The only suggestions they gave me was to move the structure scan module or by an external antenna.

I haven’t tried the HDS 5 from bow in the back yet. I will try this tongiht if I have time.

I was curious if that is what they would say. I have my LSS-1 mounted under my console so there is a big pile of fiberglass in between them.

I think I will probably leave the structure scan module where it is at and install a LGC 4000. They informed me that I need to install the NMEA network to run the LGC 4000. I think the added accuracy and the fact that I will be able to use the same antenna for both units will be nice.

Did you ask why you weren’t seeing the HDS-5 in the advanced features menu?

At first I did but after some research I learned you can not share a GPS antenna between units with out the NMEA network setup. I had the two units linked via ethernet but not on a NMEA network.

I had a NMEA 2K network set up first so I never tried using
a second antenna via an ethernet network only.

This paragraph, “If, for example, you do not want to use your unit’s
internal GPS antenna, you could use an
external GPS antenna connected to an ethernet
or NMEA 2000 network”, has me confused.

Paragraph taken from page 80 of your HDS manual.

I would think the only way to connect to an external
antenna via ethernet would be connecting to another GPS
unit with an internal antenna.

Is the information in the manual not correct or am I misinterpreting the statement?

I think that paragraph is inaccurate. I am able to share transducers between the two units when hooked up via ethenret but not a GPS antenna. I read this some where when I was researching… I believe it was on Lowrances web site but I can’t remember for sure.

Also, the only option it was giving me on either unit for a GPS source was the internal antenna of which ever unit I was trying to set.

I am going to play around with them again tonight since they did come out with the 4.0 update. I will report back with any findings. Thanks for the input Dandorn.

I moved the HDS 5 to the back by the structure scan module and same issue. It wouldn’t lock on any satellites just like the HDS 7. I also tried swapping ports and ethenet cables but nothing fixed the issue. I am convinced the structure scan module is causing interference with the internal antenna of the HDS near it. I am going to install the LGC 4000 tomorrow since it is suppose to rain and I think that will solve it.

I would check to make sure that fixed it before doing any permanent mount of the puck in case you have to move the puck further away.

For sure John. I have an idea where I want to mount it but I am definitely going to try it and see if it works before I start drilling holes.

Just an update. I installed the NMEA 2k network last night with out the LGC 4000 puck. I was able to set my HDS 7 to use the HDS 5 antenna as long as I had the HDS 5 on or in standby mode. So you can use another units intenal GPS antenna when you have a NMEA 2K network set up and if the two units are connected by just ethernet without the NMEA 2k network you can’t.