MrG
What you are saying makes sense to me. Every diagram on Lowrance's website that I have found shows that you do not connect the power period. That is where the confussion is starting from. I have e-mailed Lowrance directly and asked them as well. I will post their response.

McCloud
I sent you a PM with the e-mail address of the technical rep for Lowrance. I hope it helps!
Phill

look on page 15 of the downloadable manual for the 5200 on lowrance website. The power cord splits into three seperate cords 1. a data cord 0183 which Does NOT need to be hooked up. 2. the nmea cord which you are talking about DOES NOT need to be hooked up (because your network is already powered) 3. The third branch is to get power to your actual display which DOES need to be hooked up. Your using the option B in your owners manual

Lowrance Globalmap 5200c Owners Manual p. 15 for pcavender

Lowrance lms520c Owners Manual p. 32 for McCloud

Thanking you again for your help but power diagram A reads "Use this method if you are powering the display unit and a GPS module or the display unit and a NMEA 2000 network." Am I NOT powering both a display unit AND a GPS module?" I definately used power diagram A and NOT power diagram B. Am I wrong? I cannot believe this stuff is so complicated!

I wish you weren't so far away so I could help. Diagram a is what you should be using. When I got mine it had a separate yellow paper that showed & simplified the whole wiring process. Did yours have one? If not I can try & find mine then scan & post if you like. From what I understand 99%of the time the error message you're getting is due to lack of power/ground. Have you used a volt meter to verify all connections are good?

The tech guys yesterday DID use a voltmeter and checked everything, BUT I saw the guy tape TWO black ground wires together and just leave them dangling. Is that right or are they supposed to be "connected" to a ground plug? Could that be it? What IF my new cranking battery is only a 500-600 cold cranking amp battery and I have a 225 hp Evinrude? My tech told me that I need a much larger battery to power up that bigger motor and/or furnish enough power to my 520 unit.

Were the 2 ground wires both from your lms520? If so & they are not grounded to the electrical system then that's your problem.

MCCloud if you want to meet me at bass pro in katy or pull your boat to spring I will get the unit working. I put mine on last friday after we talked and it is working great. Not sure whats causing your probelms over the internet or phone. Just let me know something both of my numbers are posted above..



Buddy

Sorry for the confusion mccloud. I think me and mrG were saying the other guy that had a problem needed to use diagram B - not you.

Buddy, THANKS for the great offer! It may come to that if I cannot figure out the problem. Right now, Lowrance wants me to send back the module (out of commission another 4 weeks!). I am going to check those "black ground wires that I think the tech taped together" and other connections, then make a decision. I have a couple of tournaments at Amistad this week-end.

I would try swapping units with someone at the lake. That way you can rule out if it's the unit or not.

Dave, do you mean swapping modules or actual 520 graphs? I guess both would be a good idea, except my unit is built into the dash. Of course at this point, I can remove it and replace it blindfolded!

Graphs. If yours works on the other boat then it's not the graph.

McCloud the offer still stand anytime you need it. Just give me a call or a pm on here. We will set something up. I have the same unit so if we need to swap stuff around to figure it out we can. hopefully lowrance will get it fixed for you..

Did you get it working?