Gps loses signal

It would be good to make sure that the 951 software is up to date. The most recent software upgrade includes new code required due to changes that have been made to the GPS system. You can download the software for free from the Northstar web site but it requires a loader cable, power supply and a Windows based PC to perform the update. Most Noprthstar dealers know how to do this but they will charge for their time. The GPS antenna should be mounted where it has a 360 degree uninhibited view of the sky right down to the horizon to get best performance. Basicially any conductive material including pigmented paint, tinted glass or wet canvas can block the signal. Inspect the GPS coaxial cable and it's connections for any signs of corrosion or contamination. Sometimes just removing and reinstalling the connections is enough to remove contamination and get better performance. If in doubt concerning the coax and it's connections, temporaily substitute a new coax assy by-passing the existing cable to see if this makes a difference. You can monitor changes from the GPS status page. See the user manual for information concerning how to understand the numbers being presented. You should be tracking at least 4 SATs with signal levels higher than 30. Generally 95% of all GPS signal issues are related to the coax or its connections.
coax assy to v

Make sure that your GPS is mounted under the windshield so it ahs free access to signal. Aside from that, be sure it is mounted parrallel to the ground so that the screen is completely "horizontal." This model seems notorious for lack of signal ability so if that doesnt' work you may just need to put up with it until you upgrade. Best of luck!