Furuno radar inst. question

N

nordicstallion

New member
Will someone please give me a little guideance on Furuno 1715 radar display wireing.The manual shows a ground wire on the back of the display & black and white power wires to the battery. The included 3 wire coax power cable includes a ground wire.Are both grounds required?I am electronically challenged, big time! Vern/C-Dog
 
I have just finished installing my 1715. As per the manual I connected the black wire to the negative bus and the white wire by way of a fused switch to the positive bus.
It works just fine in the driveway - a bit of clutter from the trees though!
 
I re-read my post and then yours and missed an important point in yours. I did not connect the ground screw on the display to anything - it still works. I did wonder about it though. Maybe this might be an issue with a metal hull but I was reluctant to connect the cable shield or ground screw back to the negative side of the battery.
 
Dave. Do I understand correctly that you did not connect the cable shield ground to anything? Also the case ground either? Im seriously challenged by electricity & electronics so I need to pound this through my bone barrier with a marlinspike & a mallet. Thanks. Vern
 
That ground terminal on the back of the display unit is a "chassis ground." This is used to guarantee that any noise in the radar unit is connected to ground/earth. The shield covering the power cables is used to block any electromagnetic field from the DC flowing through the power cables. Those shields can float, and the unit will work. For the best performance, they should be connected to a good ground (not the negative side of the battery.) In Journey On I use the bronze through hull for the head as a ground point, and run the chassis grounds there. Try not the connect the signal and and power returns together. DO NOT connect the chassis ground to the power return.

Boris
 
Boris. Im guessing a thru hull chassis ground means it needs to be subsurface. On my 19 I thhik the only thing it has is the deck drain plug hole.Im also guessing the motor mount is a wireing system ground and doesnt count. What else will work? Vern
 
I asked Furuno USA, Inc. this question when installing the 1623 model:

"I have successfully installed a 1623 radar on a C-Dory22, and I am wondering how to ground the unit. Although the instructions say to ground it to the hull, I am wondering if it would be better to ground to the negative buss instead of a fiberglass hull."

Here was the response:

"If you cannot connect the ground to a large amount of metal, do not connect it to anything."
 
What Furuno is trying to get rid of high frequency noise, up at RF frequency. The noise on Journey On is at digital rates ( and harmonics, digital is a square wave,) so I grounded it to any metal in contact with water. If there is no metal that you have below the boat, and the radar works well, follow Furunos advice, and don't ground it to anything. That also means don't connect any wires to the grounding lugs.

On our sailboat, Our Journey, I installed a sintered bronze plate outside the hull and grounded the heck out of everything, because we were using SSB, and when you transmitted everything glowed; (I'm not kidding, the compass light lit, since it was right under the SSB antenna.)

Boris
 
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