GPS vhf intermittent connection

[SAWDOC]

Hi all
Last season I got someone to connect up my Garmin 72 GPS to my XM DSC VHF radio. All works well sometimes with accurate position displayed on the screen. Occasionally I hear the dreaded BEEP BEEP and go below to discover the dreaded "no GPS input " on the dispaly panel of the VHF. When I examine the Garmin, it is still picking up the sat signal so I guess the problem must lie in the connection between the two. I have checked the settings on the Garmin and it is outputing NMEA type data.
I'm sure anyone who has experienced it will agree there is nothing absolutely nothing as infuriating as the VHF DSC ayatollah smashing the tranquillity of a day on the water. Help please before I throw the lot over the side! /forums/images/graemlins/confused.gif

 

[Elessar]

If it's intermittent it's almost certainly a wire connection developed verdigris as you have concluded.

My guess therefore:
The NMEA connection out of the GPS will have a bespoke cable and the VHF will have one too. These two cables will have been connected somewhere, the join will have been made with a chocolate block connector wrapped in tape or cheap car type crimps. Find the join and remake it. Note it is not re-red green-green etc with NMEA so do it one wire at a time or make careful note.

I'm a fan of shrink wrapped crimps like this - they're waterproof and last. You may need to cut the cable back to get to shiny copper.