Connections

GPS/VHF Wiring, 2/9/2008

I installed new electronics last spring, but to date had not yet completed the wiring for the GPS. That means our DSC capability for the radio wasn't complete. We could make an automated digital distress call, but it would not include our coordinates. That would certainly complicate a search and rescue should we ever be unfortunate enough to need it.

On Saturday, I finally finished off the wiring. The instructions for the Standard Horizon radio indicate three connections: data in(+), data in(-), and data out. The GPS instructions only indicated data in and data out (no polarity on the data out). Standard Horizon tech support was very helpful, and advised me to make connections as follows:

VHF blue (in+) to GPS blue (out)
VHF gray (out) to GPS yellow (in)
VHF green (in-) to ground

I ran a power/data cable for the GPS to both helms, and joined them at the lower helm. From there, I ran the red and black wires to the switch and ground bus, and the signal cables to a new 4-post block. I then ran a length of signal wire up to the radio, and attached it to a quick connect so that I can easily disconnect the radio when I want to remove it from the boat. The worst part of this project was handling the very fine signal wires, which are difficult to strip and separate without cutting them.

Looking forward to trying out a ship-to-ship DSC call this summer!