I recenly bought a used boat. It came with a Lowrance LMS 330 and a 2000 series GPS puck. The unit keeps saying "can not aquire GPS" or something to that effect. I have checked the wiring on the puck as I understand that it has to have its own power source however it seems to be connected correctly. The power wire runs under the dash to the main power switch. All other wires seem to be ok, ground ect... Any ideas, this is my first boat with GPS so I am a complete rookie with electronics. Thanks in advance.

Your GPS unit is not getting a signal from your antenna. Either because of no or incorrect power to the antenna or the antenna is shot. Do you have a buddy with a GPS unit that runs off a LCG 2000 antenna?
Hook your unit to his power cables and see if you get a signal. I have had a couple antenna go bad.

Now having said the above I am assuming you are giving the antenna a clear view of the sky..
Press pages on your unit and then press status and you will get a screen that shows the avaialble satelites and what signal strength you are getting from each one. If you are getting nothing then it is your antenna. I would double check the wiring is done correctly because it can be confusing and it is easy to get it wrong.
Good luck,

I wouls suspect wiring also.

Those units are supposed to have an extra on off switch to the ant power lead so its not powered up all the time the boat isnt in use. Look for that switch, it may be turned off, or maybe it has a blown fuse or otherwise is not supplying power to the antenna.

my experince is if something is blocking the ant from reading the satellites, like something is blocking the view, it will still talk to the unit, it just wont aquire a fix.

Perchjerker is right when he says it will still talk to the unit meaning the antenna will be talking to the gps but it wont aquire a signal. So if your getting a no antenna detected warning then your gps is not talking or reading your antenna. Since this boat is new to you the suggestion of maybe the power to the antenna being switched off is a good one. Make sure the master switch is on and look for a non factory installed switch that may have been installed to de-power the antenna when it is not in use to avoid a dead battery.

I had this problem with a lms332 and a lms480. Both times I had a bad cable from the unit to the antenna. Lowrance's website has a troubleshooting page that will show you how to use a voltmeter to check the cable.

Hey thanks for the replies and ideas. I have been over the wiring and fuses 20 times and still think its hooked up ok. The guy I bought it from said it worked when he had it. I am at a total loss. I have been emailing with a customer serv. rep from Lowrance. She is currently sending me a new cable, the Y adapter one. This would be the cable that runs from the unit to the puck. To update you guys the unit's exact error message is "GPS Module Not Responding".

Look at this it may help:
http://primus.lowrance.com/support/resultDisplay.do?gotoLink=1194&docType=1000&contextId=514%3A1194.1373&clusterName=ClusterPublic&lang=english&docset=%2FDocuments%2FTroubleShooting%2FNew+Utilit y&contentId=59893452-c284-4652-aab9-46a56cf13220&responseId=135ccbe2cfd4f608%3Adcb03b%3A11bfdc8b9ee %3A104f&groupId=4&answerGroup=3&score=524&page=http%3A%2F%2Fprimus.lowrance.com%2Ficr%2FTrou bleShooting%2FNew+Utility%2FNU_GPS_PosInfo.htm&result=2&excerpt=If+the+unit+continues+having+difficulty+tr acking+satellites+or+is+giving+a+specific+error+me ssage+of+GPS+Module+Not+Responding%2C+additional+t roubleshooting+may+resolve+the+problem.&question=Troubleshooting+-+GPS+Module+Not+Responding+LMS+330&resultType=5000#Goto1194

I quick fix to not over look it to look at your battery cables that power your unit. The gps needs a full shot of juice in order to work, any little rusk on the terminals can make it not work. This was the case with my gps/depthfinder. A little sandpaper to the termals fixed my issue.

Marine damp enviroment

I slide shrink tube on 1st & then solder all wiring connections before heating S-tube... this is much better than pinch-on connecters, wire-ties & etc that might go bad w/age & be difficult to find...