Furuno 1832 Hdg Sig Missing



I have a Furuno 1832 on a recently purchased Cruisers 400 Express. This radar receives navigation data from a Northstar 958 GPS using NMEA0183 data exchanges.

I can see the position data from the Northstar GPS on the Furuno radar display so I know there is data being transferred.

What I see when operating the 1832 is that the radar completes a cycle, then it completes a second cycle okay and then on the next cycle it blanks the screen (erases the entire image) and then the image rotates 90 degrees (same image 90 degrees rotation clockwise) even though the boat is traveling straight ahead. The entire time there is a message being displayed: "Hdg Sig Missing"

I don't have a heading sensor installed, just the GPS mentioned above. Here are the data messages that the Northstar is sending to the Furuno 1832:

What could be the problem?
Your problem is unrelated to the NMEA 0183 data from your NorthStar. The problem is the loss of heading flash pulses from your radar scanner not being processed at the display. This could be caused by an issue in the display, bad cable, or heading flash relay in the scanner. I would start with the scanner cable. Check the antenna cable at the back of the display for corrosion. Ensure any splice/junction boxes don't have corrosion or water and the connections are good. Open the scanner and check your scanner cable connections there to ensure the same. If everything looks good, I would recommend replacing the reed relay inside the scanner (PN 000-118-533 $32.20 list). If that doesn't resolve the issue, you would need to have the unit evaluated by a dealer or send it to the factory service center. Based on your description of the problem; I suspect the relay.
I opened up my case and verified that my radar was turning. I'll be checking the connector on the display next but if that checks out, I guess the next step is the connector in the radome and then replacing the reed relay. When I opened the radome, it appeared everything was inside metal boxes. I couldn't see where the cable connected inside the radome, does it go inside one of the metal boxes?

Also, where is the reed relay inside the radome case?

Is there anything complicated about replacing the reed relay?
The metal boxes you speak of are sections within the radar scanner. They are covered by a metal RF shield cover that would have to be removed to see where the scanner cable connects to the board(s). The Reed relay on this unit is normally sticking up on a piece of metal so that it is near the magnet on the bottom of the spinning array. It is normally easy enough to replace.
I take it the relay is the device with the two screws in the attached image?


  • Radar Relay.gif
    Radar Relay.gif
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