Hey there. Total boat newbie here....

[ADorough]

Hey there.  Total boat newbie here.  Recently bought a 2000 Sundancer 310.  Love the boat, but haven't been able to get the GPS unit to connect.  First, replaced 15 amp fuse that was burnt out, but still didn't connect.  Screen simply shows the GPS logo with a ? on it.  Read that it may simply need to have access to open sky for a few hours...we've been out 10 hours thus far, still no connection.  Recommendations for next steps?  Appreciate it in advance!

[wingless]

What is the GPS make and model? What interface is used to the instrument? What instrument?

[Korkie]

Congrats on your new endeavor. Please try n list as many specifics as you can with questions. There are many makes and models out there. The more info you can provide, the better chance of getting an answer to your inquiry. Your first year with a boat with that age will be a lot of trouble shooting to get things totally operational. Best of luck.

[ADorough]

Thanks, all, for the guidance. The GPS receiver (where I believe the problem is) is a Raymarine 125 GPS Receiver. It is connected to my chart plotter/radar display (Raymarine C-Series, circa 2006) and to my VHF Radio (Raymarine Ray218). My chart plotter has a GPS icon in the top righ corner, which simply has a question mark over it. In the top left corner, where my lat/long position should be indicated, it is all 0’s. And on my VHF display, it says “No GPS”. Appreciate any suggestions for getting this connected!

[wingless]

This Raymarine 125 manual shows that the GPS receiver has three interfaces available, Seatalk NG, Seatalk and NMEA.

https://raymarine.app.box.com/s/elqaup3xectwbhtfl4lg/file/7028933610

This Raymarine C classic manual shows that the MFD has SeaTalk, SeaTalk² and NMEA interfaces.

https://raymarine.app.box.com/s/0ka25bb7n2c4em51aeag/file/3358518314

This Ray 218 manual shows this has a NMEA interface.

https://raymarine.app.box.com/s/55w633qmoxe4h6v5nwgx/file/204802950513

My guess is that the GPS is configured to send NMEA data to the VHF and to the MFD.

Does the 125 have power? Does the 125 LED indicator illuminate? Are the interconnections solid?

[wingless]

This Raymaine 125 manual shows what the indicator lamp modes mean.

https://raymarine.app.box.com/s/elqaup3xectwbhtfl4lg/file/6772514585

[wingless]

My error, the first link was for the Raymarine 125 Plus. This is the manual for the Raymarine 125 GPS.

https://raymarine.app.box.com/s/elqaup3xectwbhtfl4lg/file/6772514585

It has NMEA and SeaTalk interfaces.

My guess remains that the NMEA interface was used for the installation.

Again, start w/ the LED status light, then check the wiring.

[ADorough]

This was so helpful, Wingless. So, the unit is flashing green every two seconds, indicating it has a fix and is running NMEA as you suspected. When you say check the wiring, what exactly am I checking for?

[wingless]

Glad to help.

Good info.

That green flash every two seconds also indicates the 125 has power.

The 125 knows it is NMEA and not SeaTalk because the Green wire is connected to +12VDC.

Find the end of the 125 cable. There should be a junction at that point to the C Classic NMEA cable and to the Ray 128 NMEA cable.

Inspect those connections. They should be solid. They should match the documentation.

https://en.wikipedia.org/wiki/NMEA_0183

The 125 is a "talker". The C and the Ray 128 are "listeners".

[wingless]

Sorry, another typo, for NMEA the green is NOT connected to +12VDC, that's how it knows it is NMEA.

[ADorough]

Ok, dig into wiring, sort of. Traced the wire jacket from the spoiler to the back of the chart plotter and it appears to have a plug on the end of it that plugs directly into the back of the chart plotter. There are no exposed wires. I can’t quite reach the back of the chart plotter to remove it. Any further suggestions, or should I resign myself to hiring someone to trace it down? Thanks!

[wingless]

Examine page 27 of the linked C Series manual.

It shows the NMEA connector that plugs into the rear of the plotter is part of a 1.5m cable.

Examine page 20 of the Ray 218 manual. It shows there is also a short cable from the NMEA connector.

Locate where the three NMEA cables meet. Determine what connections are made at that location.

Or, get someone to trace / resolve the problem.

[wingless]

These connections for wiring of that vintage was either in a Raymarine box, as in the link, or in the open in these 3M Scotchlok connectors.


https://www.ebay.com/itm/Raymarine-Boat-Auxiliary-Connector-Box-D108-Carver-Seatalk/401497569774?epid=2070939046&hash=item5d7b1eb9ee:g:yZwAAOSwgkhakEKt

[wingless]

It looks like the best access to the rear of the plotter is attained by removal of the ell-shaped rocker panel plate.

On mine, all those wires route to the starboard side, so I lay a towel onto the window lip, throttle levers, then pivot that panel out of the way.

My guess is those connections are accessed behind that switch plate. There is also wiring access behind that large starboard bin, at the helm, next to the operator's knee.


http://images0.boattrader.com/resize/1/6/54/6320654_20170802123142870_1_LARGE.jpg?t=1268037

[HAT]

I had a similar problem on my 99 Sundancer 34. It turned out that there was a 1.5 amp sure in the antenna feed. Once I replaced that the GPS came on line and works like a champ. You really have to hunt to find it so look for the small red lead going into the main GPS coax.