NMEA 2000 blowing fuse / ais not powering up

[NYSail]

So have spent the weekend so far hooking radar up..... works! Next was the AIS and NMEA 2000. Have everything wired and am having issues. Starting with NMEA...... and please pardon my elementary electrical knowledge.

NMEA power is connected to same 10A breaker that chart plotter is....Chart plotter is working fine. I tested NMEA power cable prior to fuse and am getting 12.4v. However without even connecting power cable to backbone the 3a fuse blows. What could be causing this??

Now with ais..... Garmin ais 800

I know the NMEA is not connected however when I attach power the unit flashed for o e second if that then no lights..... tested wire where is connects to ais unit and am getting 12.4v. Is it that the NMEA cable is not connected?

Help.....

Thanks!
Greg

 

[JohnShannon]

So you are just attaching a cable to your electrical system and a fuse blows. Something is wrong with the cable.

 

[jssailem]

A fuse blowing causes me to believe that wiring has a short. The fuse is trying to protect you. Check all of your connections for stray wire strands not properly constructed. check all of the connections to be sure the red went to Positive and the yellow (or black) went to Negative.

 

[NYSail]

Well that does kind of make sense.... possible faulty wire. Connections are perfect and I do get proper voltage from before the fuse but when I put in line fuse together it blows...... and this is with the wire NOT attached to the NMEA backbone. So all I’m looking for is an energized power cable and I’m not getting it......

Thanks

 

[dlochner]

The power cord in question is the cord that plugs into the backbone, correct? Is the NMEA 2000 connector, the part that attaches to the T on the backbone, a field installed connector or a factory installed connector?

Are you plugging it in to the T or the backbone, it makes a difference.

Check for resistance between the + and - out put pins. These will be the 2 largest pins on the connector, if the pins are all the same look for a Pin Out diagram for NMEA 2000, should be easy to find on the internet. There should be infinite resistance between the two. If there is continuity, or zero resistance then there is a short in the cable.