The dreaded Lowrance "GPS module not responding" hit me a few weeks ago. I would disconnect everything from the unit for a few minutes, and when powered back up the signal connected briefly before losing it again. All the wiring in the cuddy-dash area was in good shape, but I tested and cleaned all connections, tried resetting the unit (LMS 525c), even did the software upgrade which did provide some new features and rearranged some of the menu items to a more usable location. This did help, it would stay up for a 1/2 hour before losing it again.
Then I went to the battery box in the stern, the cables connectors were a bit rusty, but not too bad. I removed a panel exposing the wiring behind the 2 way switch and there was a ton of rust and corrosion on the bus bar connecting the engine/batteries/switch/front bus. Replacing all terminal connectors and battery cables did the trick. Applied a good coating of grease to all exposed connectors.
Unit works great now, has "Position Acquired" a few seconds after power up !! Still spent over $100, but better than $249 for a LGC-3000.
Then I went to the battery box in the stern, the cables connectors were a bit rusty, but not too bad. I removed a panel exposing the wiring behind the 2 way switch and there was a ton of rust and corrosion on the bus bar connecting the engine/batteries/switch/front bus. Replacing all terminal connectors and battery cables did the trick. Applied a good coating of grease to all exposed connectors.
Unit works great now, has "Position Acquired" a few seconds after power up !! Still spent over $100, but better than $249 for a LGC-3000.