Garmin to DSCVHF

[Stix]

My old garmin chartplotter (235) has a GPS/NMEA multicable to connect to a DSC. There is a black and red cable in this group as well as an input in and an input out. do I need to connect these as well even though both devices have their own power inputs. To be honest Im a bit nervous about connecting up wrong. Could I do some damage if I did?

 

[alldownwind]

You only need to connect NMEA-out +, usually a blue wire on a Garmin but check your manual, and NMEA-out neg. The latter, on all the boats I have had, is the ship's negative anyway, so actually you may only need to connect the blue (Your DSC radio is already connected to negative via its neg power lead).
And no you don't need to connect any other wires.

 

[davidpbo]

I suspect 2 of the cables are your data out and two for power (12V) in to the GPS/Plotter. That is the case for the cable to my Garmin GPS Map 76 but you need to confirm that is the case for your unit.