Lowrance 330c gps not responding

I have a 525... Several things and go step by step... First, make sure your getting 12v of power to your "puck"... On the Lowrance site there is a step by step guide for testing. Just because your getting power to the main unit does not mean your getting power to your the gps module. There are three different power sources on these units. Main power, sonar and gps! If your getting 12v coming out of the data port then check power to the cords, and to the T... If all that is correct the its likely your gps module. You can order a new one directly from Lowrance customer support for 50% off the normal price as a replacement. They will likely upgrade you to the 4000 series. Comes with all wiring, T connector but not the resistor cap. Best time to call Lowrance is 8:15 am central time when the phones are turned on!

Hope its not to late, before you replace (buy a new one) call Lowrance. I have a 525 and working through some problems and they advised me that they would replace my unit for $200 no questions asked. To answer your question not 100% positive but I did see a recent question where Lowrance lost his unit and sent him the 525 as a replacement and the connections were different. I believe my 525 has a 5 pin system with one notch. Does yours have a external gps module? The 525 does!

Make sure that you have powered the NMEA 2000 network. The display unit's power cable has a set of red, black, and sheild wires that need to be hooked up to a 12VDC power source. There is a power diagram somewhere in the manual that should show this.

Make sure that you have the NMEA 2000 network connected properly. If it is a newer version LMS-525, it should just be a single 15ft cable that has two female ends, the module plugs into one end, and the other end plugs into the back of the display.
If it came with some T connecters and 120Ohm Terminator caps, then make sure you have that hooked up correctly. There should be a diagram in the manual for that as well but you just connect the two T's together like TT, put the 120Ohm terminators at each end, and run the extensions to the display and GPS module.

There is a decent troubleshooting guide for checking to make sure power is getting to the module at http://primus.lowrance.com/support/resultDisplay.do?gotoLink=92&docType=1000&contextId=426%3A92.273%2C600.639%2C92.113&clusterName=ClusterPublic&lang=english&docset=%2FDocuments%2FTroubleShooting%2FNew+Utility&contentId=42296cce-4f9b-40c8-9dcf-33d5df754009&responseId=135ccbe2cfd4f608%3A1fe88d%3A1225c5cc17c%3A-bac&groupId=4&answerGroup=1&score=986&page=http%3A%2F%2Fprimus.lowrance.com%2Ficr%2FTroubleShooting%2FNew+Utility%2FNU_GPS_ModNR.htm&result=0&excerpt=Module+Not+Responding+The+GPS+module+not+responding+(early+GPS+products+may+also+indicate+coupler+not+responding)+indicates+that+the+unit+and+module+are+no+longer+communicating.&question=gps+module+not+responding&resultType=5000#Goto92

If this doesn't tell you anything, most likely the GPS module is bad.You will need to contact Lowrance support to get it repaired/replaced. You can call them at 800-324-1356 or email them at http://www.lowrance.com/en/Support/Product-Support/Contact/

Check the connectors and wiring between the GPS module and sonar unit. If it's an internal GPS module yo may have knocked loose a connector internally.

have a lowrance lms-330c the depth no. keep changing from hi no. to low no. can not stop it,,, will not show true depth,,, can you help?,,,where can i send it to get it fix?

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.

A "soft reset" can be accomplished by pressing and hold "Pages" key and press and hold "PWR" key till USA map comes on , then release both. A "hard reset" requires press and hold both "Z in" and "Z out" buttons and press and hold "PWR" button releasing all three when USA map appears.

check the power connections to the antenna

hi,your gps module-antenna is powered into 12 volt same as unit,have you traced your cable-fuses etc
john

i found that it was the gold maps in the mmc card reader. Remove card and see if it fires up. Also i can be the 60 ohm resister on the NMEA 2000 y cable