My LMS-522C keeps losing it's position on the GPS.

Try page 212
http://www.lowrance.com/Root/Lowrance-Documents/LMS527-522_0152-181_120406.pdf

what do you have your unit hooked to too power up straight off the battery or thru a power switch if thru a switch hook it straight to bettery

You can get the manual on the link below.

http://www.lowrance.com/upload/Lowrance/Documents/Manuals/LMS527-522_0152-181_120406.pdf

Chances are your GPS puck antenna is bad. They have a pretty bad rep for failing and since its now at least 5 years old , you have been on borrowed time. You can get replacements on Ebay. Your temp issue is unrelated . Might be time to upgrade.

Go into your gps settings in the menu and then select "Initilize GPS". That will basically reset your GPS and it should find your location. It can take up to five minutes so initilize it and crack open a cold one. when you get back your location should be on the screen.

I have this problem as well! Mine is on the LMS 332C

If it is normal in deeper water, it is most likely just returning stuff in the water (debris, algae, anything floating around...choppy water can cause this). Try installing the latest updates from http://www.lowrance.com/en/Downloads/Product-Software-Updates/

If it doesn't help, adjusting the sensitivity or setting the SURFACE CLARITY option from the SONAR FEATURES menu to LOW, MEDIUM, or HIGH...whichever gives the best results.

BAD KEYPAD.

I hate to be the bearer of bad news, but it sounds like your internal module is on the fritz. I am pretty sure you can buy a external puck and a harness and it will work perfect. I did that with my hummingbird 997.

I am having the same problem as joshuwan36 with my LMS 332C