pjbharrison 2:31pm, 8 June 2012
Just bought a new Cobra MR55 radio and want to connect it to Garmin GPS 75 without frying both.Anyone else done this already?

GPS manual says

*Connect the brown harness lead to the NMEA "A" line of a two-wire, shielded cable.

* Connect the black harness lead to the NMEA "B" line of a two-wire, shielded cable.

*Connect the black harness lead to the shield of the shielded cable. (The opposite end of the shield should not grounded.)

The radio came with a short lead. It has a plug on one end to go into the radio and two bare wires on the other end, 1 red, 1 black.

Skykomish E29 Posted 6 years ago. Edited by Skykomish E29 (member) 6 years ago
looking at my instruction book the NMEA cable should have an 8 pin plug with 8 wires (obviously) Brown, red, orange,green Blue Grey and purple plus Shield, Assuming that your radio has a DSC capability I would have thought that the NMEA cable would have come with it, however it sounds like you only have an external power lead??????? My radio is a NASASX35 by the way
rothwell_neil Posted 6 years ago. Edited by rothwell_neil (member) 6 years ago
The NMEA output only requires 2 wires to work, manual should tell you which ones they are? My radio has 8 pin on back for all sorts of other stuff other than NMEA, it will be of no help but for me the yellow and green are the NMEA inputs and connect to the red and black out of my GPS! As it is a signal it shouldn't fry anything if you get them wrong.
Skykomish E29 6 years ago
mine are
NMEA RX+ brown
NMEA TX + Orange
Ground / TX - shield
NormanKlipspringer Posted 6 years ago. Edited by NormanKlipspringer (admin) 6 years ago
Every manuafacturer and even different devices with the same manufacturer often have different wiring arrangements. I have just looked up the GPS75 manual. There is a wiring diagram on page C3 (myarchive.us/richc/GPS75_OwnersManual.pdf). Brown to red of radio and black to black (signal ground). In my experience I have often got this wrong and never fired anything. You only need to connect the gps NMEA out to the NMEA input of the radio. Once you have connected the wiring it still wont work until you switch on the interface to nmea in the GPS menu system (section 6.7 in the manual). It took me two weeks to discover this the first time I did it.
Good luck
pjbharrison 6 years ago
Thanks for the replies guys.
Got it working today.
Now to get a MMSI number!
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