LCX-15MT. GPS not locking on consistently

[eyegetit]

Just when I think I have this unit figured out....

Once my GPS locks on to WAAS/WGPS, I have no problems for the rest of the day. Trouble is, locking on seems to be a hit or miss proposition during my first hour or so on the water.

I thought I had it all figured out when I discovered that the unit would lock on immediately as long as the power cable had not been disconnected from the battery since the last time it locked on. Of course I have to disconnect the power cable to charge the battery, so after the battery was charged I would reconnect the power, turn the unit on in my driveway and come back an hour later to shut the unit off after it finally locked on. Now I'm ready to hit the water. WRONG!! Now it's starting to do it all over again. GRRRRR!!

By the way, my unit will ONLY lock on when I have the DGPS enabled. I've tried it without the DGPS and it has never locked on for more than a few seconds at a time. My GPS receiver/antenna has a clear line of sight. I have also tried every mathematical combination of WGPS, Position Pinning, and Track Smoothing to correct the problem without success. I am running the latest software version (2.5).

I've had a cheap Magellan hand held aboard my boat for the past 5 yrs and it has NEVER had a problem locking onto the satellites within seconds after being turned on.

What gives?? Any suggestions?

[John]

I have an X-15MT w/GPS as well, although I have not had that particular problem. I would bet that it is a software related problem. I had a problem in which the trail that I was marking would suddenly stop and the display would produce either a straight vertical or horizontal line. As I continued to travel across the lake, a second and parallel line would appear. I finally called Lowrance and talked to their customer service. They didn't have an answer. I then requested to talk to their software folks and they were aware of the problem and did tell me that it was software related. If you call Lowarance and get no satisfaction from their customer service, ask to talk with their software people. Let me know what you find out.

[Stormsearch]

Does the unit give you any error messages? There is a typical problem with the NMEA interface wires shorting to each other on the power cable. All of these wires must be protected from each other. In this instance, a "GPS Module not Responding" error was produced. If you are getting a different error, then I agree that it is software related. Good luck.

[eyegetit]

Yes, "GPS Module Not Responding" is the error I am getting most often. I also get a lot of "Position Acquired" quickly followed by "Position Lost".

I sent a detailed email to the tech support group at Lowrance yesterday. I am waiting on a reply.

Thanks.

[DMMoore]

I am having the same problems. This is the second power head I have had. The first on worked well but would not stay off. This one will not lock on gps, just like yours. Please post what they tell you at lowrance. Douglas

[Stormsearch]

Check your NMEA interface wires!

[eyegetit]

** UPDATE ** Here is the reply I received from Lowrance. Looks like I misunderstood some of the function keys. I thought "Show WAAS Alarm" was just that...an alarm! I didn't realize it enabled/disabled the WAAS function. Nowhere in the manual does it mention WAAS and DGPS canceling each other out. Oh well, we'll see how these suggestions work out. Thanks for everyone's help.

-Terry

November 21, 2002
5:48 PM EST

Thank you for your inquiry. You should not be using Differential, with the WAAS enabled. They counter each other. Under the GPS Setup menu, please select Require DGPS and deselect Show WAAS Alarm. Verify that the DGPS Setup is correct for your area. Try selecting GPS Auto Search on the same menu. Verify that the colored NMEA wires, on the power cable, are taped individually to avoid contact. Verify the power level the unit is receiving from the main battery. The voltage window is shown on the Status Window under the Pages menu. It should be showing a minimum of 12 V, no less.

If the problem continues, please contact Customer Service, at the number shown below. Have the product serial number available and a representative will assist you with a return authorization. The unit will need to be sent in for testing.

Thank you for choosing Lowrance.


Lowrance Customer Service
12000 E. Skelly Dr.
Tulsa, OK 74128

Customer Service: 1-800-324-1356
Lowrance website: http://www.lowrance.com

LEI: Parts & Accessories 1-800-324-0045
online at http://www.lei-extras.com

[Denied]

I am not sure I completly understand. If you have differential (DGPS) you will have an additional antenna. If not then DGPS should "require DGPS" should not be checked. If you have waas you should be using it as it is slightly more accurate then the DGPS.
Dean