extending GPS power and data cables

[JSL3]

I just bought a Garmin GPSMAP 478 (after 7 years using my trusty Garmin GPSMAP 76S) and am loving it. I want to permanently wire the unit at the helm but the cable included is incredibly short (perhaps 3 feet or so). I can easily get some marine grade 2 conductor cable to extend the power and the ground but what type of cable would you use to extend the other 7 communication cables? Thanks in advance.

[hellosailor]

Jim, I'd guess Garmin makes an extension. They all look like plain 18-20g tinned stranded wire and I really have no idea where to get that pre-made in a bundle with different colors--as opposed to buying 25' or 50' spools in each color. the odds of finding a multi-wire bundle with the right colors or same wire type...I'd ask Garmin first.

[labatt]

Cut at your own risk, as I did with our Raymarine. In other words, the manufacturer will always tell you not to cut the wires, but there's really no other way to lengthen them. I would recommend getting tinned wire in the same gauge as the wire you are splicing too. Check out this link and see if it fits your need. Preferably use GOOD quality heat shrink butt connectors to connect the wire up. It worked for me, but your mileage will vary... BTW - I've ordered from GenuineDealz.com before and it was a good experience.

[JSL3]

Originally Posted by labatt

Cut at your own risk, as I did with our Raymarine. In other words, the manufacturer will always tell you not to cut the wires, but there's really no other way to lengthen them. I would recommend getting tinned wire in the same gauge as the wire you are splicing too. Check out this link and see if it fits your need. Preferably use GOOD quality heat shrink butt connectors to connect the wire up. It worked for me, but your mileage will vary... BTW - I've ordered from GenuineDealz.com before and it was a good experience.

Thanks labatt.
This site is just what i was looking for. I had been to defender and west and found nothing.

[hellosailor]

" Raymarine. In other words, the manufacturer will always tell you not to cut the wires" True, for radar cables. But this Garmin is just a GPS connected with plain 12v power wires and NMEA/RS232 data wires, and those two standards are way less sensitive to wiring than radomes are.
If a tech told me not to cut these type of wires, I'd ask them to close the ****** and escalate me to the next level of support, to the person with the grayest hair in the room.

[Faster]

I recently installed a Raymarine wheel pilot - and cut all wires to fit the installation - they were mostly way too long. It works fine. As Hellosailor points out, it's just wire (as long as it's not radar cable!)

[negrini]

Jim, if do it correctly, it will surely work. If you're extending both data and power cable, use separated cable. You GPS take just a tinny amount of amps, so you'll not need a big gauge, say 8AWG. For the data wires, I suggest you to use shielded pairs of small gauge (unless you plan go over 300ft). Those old terminal RS232 cables are a perfect fit. Another important point is the routing, so avoid your engine room, high loads like alternator, charger, etc to reduce at minimun the chances for noise on your data wires. I did the same to my 276C and still works fine. NOTE: I always cut and splice my Raymarine radar cable , and never had any problem with that.

[JSL3]

Thanks all (Helloailor, Faster and negrini).
I appreciate the help.