Lowrance LGC GPS puck not working

[baitcaster]

Has anyone else had problems with their GPS puck not being able to lock on satellites? The puck has a direct shot at picking up the signals. Is this something normal with these pucks not working after 2-3 years? Does Lowrance fix these if they don't work anymore?

[reddog]

LGC 2000, 3000 4000? which one.

I recently hooked up my 520 that was working when it was shut down last fall. (everything taken completely out of boat because I was going to sell it this spring).. I decided to clean it up and try to market it, and took my power source and hooked everything up to make sure everything was working properly before I put it up for sale.

I couldnt get any lock on the LGC3000. I tried everything I could from checking connnections, initializing the gps again soft reset, hard reset, and got no ability to lock on.

I went to the local dealer and he had a LGC4000 on the shelf that he was willing to let me try, so I could at least determine of it was the module or the 520 itself. I had it hooked up in the truck, so it was a simple as walking out and plugging it in. It locked on in 20 seconds.

I called L at 11:04, waited till 11:08, and a recording came on telling me that there were 21 in front of me, and I could chose to stay on the line or leave a message with my number and a CS rep would get back to me. A CS rep called me back at 11:19.

I explained my situation, gave them the serial number off the back of the module.

My options were to try to find a used 3000,(and probably have to pay for that also) or upgrade for $112.00 for the LGC4000.

Even though I'm selling (or planning to) I decided to pay for the upgrade.

I suggest you do the same diagnostics as I did, to verify that it for sure is the LGC module and not the unit, and go from there.

[baitcaster]

Thanks for the quick reply. I also have a 520C that I moved to the bow as I bought an HD-7 for the dash. I have also tried the resets etc. and still can't get a lock. I can get it to get 4 bars about 1/2 reception, but won't lock. I am sure I will go through the same with them when I call tomorrow. Bad transducer last year , now a bad GPS module??? Makes me wonder. Anybody else out there with GPS troubles?

[PerchJerker]

Anybody else out there with GPS troubles?

We hear of problems with the pucks occasionally ---- not very often when you consider how many are out there. I know of several that are going on 6-8 years of trouble-free service, including one on my own boat. Most of the problems I've personally seen with them have been due to incorrect installation, ie. powering the network multiple times instead of just once, but we have run into ones that have just plain worn out or quit working.

The process reddog described is the best way to test them ---- if you're not getting the 'gps module not responding' message, the next-best thing to do is to try to test a different antenna in your setup to see if it locks on.

Since you have an HDS with a built-in antenna, you could network your LMS unit to your HDS unit and share the antenna in the HDS. Depending on what you're looking to do, that might be a better option than buying a new puck.

Good luck getting it worked out.

[baitcaster]

thanks Perch Jerker. Now you have me thinking. What do you mean by double powering. I have two positive and two negatives going to my power source when I hook up my power/data cable to the back of my 520C.

I would like to link my 520 with my Hds-7. What do I need to be able to do that. Will that allow me to use my GPS functions on my 520C on the bow or just see what is on the screen of my HD 7. Would it just take an ethernet cable going from the back of my HD unit to the 520C?

Thanks for helping me out on this.

[PerchJerker]

One set of black/red wires powers your 520, the other set of black/red wires powers your nmea network. The GPS puck is on the nmea network and you need to have the network powered for the GPS puck to work. If the network is not powered then you'll get the 'gps module not responding' message when you turn on your 520.

The nmea network is supposed to be powered one time only. Sometimes guys will power the nmea network with multiple head units, or with a power node / t-connector in addition to a head unit. Many of the failures we've seen have been when the network has been powered more than once.

If you tie your HDS and LMS together with an ethernet cable you'll be able to share waypoints, but not GPS position. You need to network them via an nmea network to share GPS position (the nmea network will share waypoints too). The network consists of a backbone cable, and t-connectors and cables to connect to each unit. It can be powered through your 520 or through a power node / t-connector, but not both. It'd be about $50 bucks or a bit more to set up the network for your 2 units.

[Matt Johnson]

In order to fully network a HDS unit with another unit you will need to go through the LGC-4000 module. Unfortunately you can't network through the internal GPS of HDS unit. LGC-3000 pucks won't even work... the HDS systems are picky

However, like mentioned, you can use the Ethernet cord to share some info and the network cords to share other info, but you will still be limited to using different antennas to lock onto GPS signals, which can somewhat deplete the purpose of keeping things clean and most-efficient.

My advice would be to purchase the LGC-4000 and network both units to that, especially since all the variables of the system will be red/black connectors. Forget about the Ethernet cord and run everything through a red/black backbone. You will notice that everything performs much better because that LGC-4000 is second-to-none and the speed/accuracy with blow your mind. I have two HDS units networked through a LGC-4000 on my boat and I will never consider using the internal antenna anymore, not even a comparison. Even though the new internal antennas of the HDS units are nice, you can't even put them on the same level as the LGC-4000.

Since you already have a red backbone running your 520 (due to the old LGC-3000) you won't need too many more parts. You can buy a Lowrance kit that will allow you hook up the whole ball-of-wax...

N2K-EXP-RD-2: Part #:124-69 ($59.99)

Includes 1 TR-120M-RD, 1 TR-120F-RD, 2 N2K-T-RD, 1 15' N2K-EXT-2RD and 1 Bus Power Cable

If networking two HDS units in the future you will need that power cable to power the LGC-4000/network because due to the internal antenna on the HDS there is no external/additional power running the module (4000) like with the older units. Most people forget that step and can't understand why they can't get their new LGC-4000 module to work with the HDS systems. ALSO, remember to go into your Satelite Settings and make sure the LGC-4000 part is selected as the source and not the internal antenna.

When hooking everything up, you will also want to make sure each "part" of the system has a T-connector associated with it. So... the HDS-7, 520, LGC-4000 and network Power Cord (if you decide to add this) all need a T... for a total of 4 T's. Also remember to use 120-OHM Terminator Ends and not 60.

It sounds complicated but it's really not. I help setup these systems all the time and once a picture is drawn out it makes perfect sense.

If you're ever in the cities and want to swing by Thorne Bros I can set everything up for you right in the parking lot...

[PerchJerker]

In order to fully network a HDS unit with another unit you will need to go through the LGC-4000 module. Unfortunately you can't network through the internal GPS of HDS unit. LGC-3000 pucks won't even work

I have to disagree with that Matt. You can network them with the internal antenna in an HDS, or with an LGC-2000, LGC-3000, or LGC-4000 puck. We've done it with all of them. As long as the GPS receivers show up on the nmea network, they can be shared.

I agree 100% that it's a lot easier than it sounds, and that the faster update rate in the LGC-4000 puck is outstanding

[Matt Johnson]

That's new to me then... I just got done talking with our Lowrance rep and we were told that only the LGC-4000 can be used as an external module for the HDS units? Otherwise it will just run off the internal antenna of the HDS unit when conneceted to an older module. They said it gets confusing because customers think the HDS unit is pulling signal from the external module but it's actually only pulling a signal from it's internal antenna.

We've tried hooking HDS units into a LGC-3000 network but it doesn't pull from the 3000 module, but rather from it's internal antenna... yes, the other unit (older unit) attached to the LGC-3000 network will pull from the 3000, but that's it... so it gets confusing...

Are you sure you've seen the HDS pull signal from a 3000? Or is it just pulling signal from the internal antenna of the HDS? Not trying to argue, just looking to make sure I have things right, because our Lowrance reps are telling us otherwise...

I think what's going on with the HDS systems you network with LGC-2000 or LGC-3000 modules is that they are just sharing info through the network (waypoints, trails, etc), but not actual satelite signal... because the way our Lowrance rep explained it is that the only two modules that a HDS unit will accept for acquiring a signal is either it's own internal antenna or a LGC-4000...

[PerchJerker]

I'm positive HDS units work w/ LGC-2000 and 3000 pucks.

You can set up the network to automatically use whichever antenna gives you the best signal, or you can set the network to use a specific antenna. When you go into the devices menu it will show you which antenna is the active antenna --- you can do that on any of the head units connected to the network, and it will show you which antenna it's pulling the GPS data from.

The LGC-4000 works with older units, ie. pre-HDS units, but they won't get the benefit of the 5x faster update rate. Only the HDS units will get the benefit of the faster update rate from the 4000 ---- I don't understand that, but that's what they say.

My own boat is an example of how the network can work with the older antennas. I had an HDS-8 on the console and an LGC-2000 puck near the transom. It was about a 50/50 split of using the HDS for the GPS signal or using the LGC-2000 for the GPS signal when the network was set to automatically take the best signal. I also have them networked to an HDS-7 in my bow. When the HDS-7 is powered up the network is almost always using the 7 for the GPS position, because it has the best unobstructed view of the sky. But I could set the network to use just the LGC-2000 puck. I've seen it work like that in other boats too.