How do I get my Google GPS Navigation to work?

Hi, the Google maps navigation has always worked fine on my phone. The other day I was out all day driving around and used the navigation the entire day. At the end of the day I tried to use it and got a different looking screen than usual and the message searching for GPS. The next day I couldn't even see the map I would just get a light blue screen with the my location dot blinking. I uninstalled updates but still had the same problem with the factory version. So today I rebooted my phone and uninstalled updates and reinstalled them. Now I can at least see the map but I still have the same problem with the navigation. What I don't understand is how can it find my location but can't find the GPS for navigation doesn't it use GPS to find My Location I am really frustrated because I am leaving for vacation on Wednesday and was planning on using it alot during my trip. Anyone else have similar problems any advice.Thank you