Electronics refresh

Just before Christmas, last year, we decided to sail from Kemah to the Flower Gardens and back to get practice with how we worked through night shifts etc. We estimated it would take about 2 days to get out there at which point we’d tie off to a mooring buoy have a bite to eat and then head back. Unfortunately the weather had other plans and we ended up beating into winds in the high 20’s and 8-10 foot seas.

The boat was more than capable of this, and neither myself or Debbie are prone to sea sickness, but the autopilot spat the dummy out. Every time Debbie was on watch, throughout the night, it took it upon itself to do a 360 through the wind and all hell broke loose. At the same time the instruments would either show a loss of GPS or compass bearing. Debbie was starting to think I didn’t believe that she had done nothing to bring this about. I had seen the boat do this a few times when we delivered it from N Carolina, but as it always had sorted itself out had never prioritized fixing it. Now I realized that if we were to be making extended trips offshore this would not fly. Most of the existing equipment was also at least 10 years old.

We decided that the electronics overhaul, which had been planned for shortly before our leaving, would have to be moved up to before our next trip offshore.

The existing setup consisted of B&G instrumentation that encompassed thru hull transducer, anemometer, flux gate compass, rudder feedback and control unit and a Smith Industries hydraulic autopilot ram that was made the same year as the boat. There was also a separate Raymarine C80 chartplotter hooked up to a radar. The. There was no link between the two systems.

After much research I decided to go with Garmin for the replacement system but I chose to keep the hydraulic RAM for the autopilot as it was a “dumb” unit and therefore was unlikely to have had any bearing on the issues we had offshore.  A quick and dirty schematic of the planned installation along with the load equivalency numbers can be seen below.  It is VERY important to carry out the load equivalency calculation to ensure that you have the required supply voltage throughout the NMEA backbone.

Sol Purpose

The project started by the removal of the old gear including all the old wiring under the sole up the mast and up the angle guard. This is an example of where the previous installers had cut corners and ran the wiring over the water and fuel tanks just under the sole. This avoided the more time consuming run through the cable tray as the cable tray was full of wiring that went nowhere and would have had to be back-pulled to get the then, new wiring in.

The old chartplotter was mounted in a cradle on top of the angle guard and the B&G were on a four instrument pod. As I was going to install a GPS6212 with autopilot and instruments head units I went with the GP1170 from NavPod. This turned out to be just big enough to mount the instruments.

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As I was unsure of whether the NavPod would fit all three instruments I called the manufacturer who told me that he had not tried that configuration before and that he could not guarantee it would all fit.  He offered to send me an old and already cut front part of the unit so I could test fit it without worrying about being unable to return it if it didn’t work.  After much fiddling around with it I was able to get it to fit like a glove.  All I had to do was to shave a small section off the cooling fins on the back of the 6212 so that one of the mounting screw heads did not rest against it.

On to the mast.  As the Z-spar mast had a cover plate on top I had planned to take it down and carry out all the work required there.  This would consist of…

1. replacing the VHF antenna with one optimized for VHF and AIS
2. replacing the anemometer with the Garmin unit
3. replacing the regular anchor light bulb with an LED from IMTRA

If I could do all this down on the deck then the remaining work to be done aloft should have been much quicker. Boy was I wrong.  Once the work on the cover plate was done it was time to head up the mast and rerun the wiring.  I had attached messenger lines to the old wiring when I pulled it out and would use these for running the new lines.  This would consist of…

1. LMR-400 UltraFlex for the AIS/VHF cable
2. LMR-400 for the WiFi antenna
3. Garmin  cable for the anemometer
4. duplex cable for the mastheads light

To prevent mast slap, the Z800E mast has 2 PVC pipes which are used to contain any wiring.  These are sliced down their length and the pipes slid over small protrusions that run the length of the mast.Sol Purpose

These sit further forward than the holes drilled in the mast cap to accept the wires and so are, borderline, impossible to feed the stiff LMR-400 into.  For this reason the rewiring of the mast had me aloft for 8 hours straight.  Thanks to Debbie and Brad, Debbie kept me in beer and sandwiches during the process and Brad was down below at the mast base

With the wires run I was able to re-install the cover plate but had no energy left to drill, tap and affix the WiFi antenna that was for our Clear broadband.  I did this a few weeks later

Sol Purpose

To allow for mast removal, I terminated all the wires that ran up the mast in the cupboard just forward of the mast under the bed.  This meant that all connections were out of the bilge and away from agents of corrosion

Sol PurposeThe wires exiting the picture bottom left lead to the most forward cupboard under the bed which held the autopilot CCU, far away from any magnetic sources.  Under the drawers between the cupboards was where I connected all the pieces of equipment in the front of the boat (AIS, CCU, anemometer, transducer)

Sol PurposeThe NMEA 2000 backbone was run through the cable tray under the cabin sole through to the small cupboard in the bottom of the lazarette. along with this wire I ran the duplex for the anchor light and new triplex for the steaming/foredeck light (I only replaced this wiring from where it connected at the mast base.  I may look into replacing the wiring in the mast but this can wait till the mast is removed, possibly next year for a total replacement of all the standing rigging).  The last wire in the bundle was the autopilot CCU/ECU interconnect cable.  I had to use a little Yellow 77 Plus wire pulling lubricant to get the bundle through the wire run which was made up of a 1.5″ corrugated pipe which took several 90º turns on its way to the lazarette.

On the underside of the cockpit sole I tied in the NMEA power, the ECU for the autopilot and the GPS19x then ran the NMEA backbone up the angle guard and into the NavPod.

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In the NavPod I connected the chartplotter and the other two instruments and terminated the backbone.  Since I had replaced the old instrument pod I also replaced the duplex wire that was for the 12V lighter socket and reran the VHF remote mic wiring as well.  In total there were six wires running up the angle guard:

1. 12V lighter socket
2. VHF remote mic
3. NMEA backbone
4. power for the GPSMAP6212 chartplotter
5. GHC10 data cable (part of the CCU/ECU interconnect cabling)
6. GMR18 HD radar marine network cable

For the autopilot, I mounted the ECU on the back wall of the rear quarter berth in the engine room.

Sol PurposeI tied this into the original hydraulic ram using the GHP12 drive unit power cable and rudder feedback cable.  I calibrated the B&G linear feedback unit based on an article I had found online and then connected that to the Garmin cables.

Sol Purpose

The dockside wizard section of commissioning the autopilot performed without issue and the sea trial wizard was equally successful.  Hats off to Garmin’s techs the setup was pretty simple.

The new radar was mounted on the existing Questus mount along with the GPS19x and the GA30 GPS antenna for the AIS unit.  The AIS unit I mounted inside the boat in the port side settee back cupboard.  Its NMEA connection ran forward and connected to the backbone under the drawers (see above) and its power and GPS cabling ran backwards to the lazarette and electrical panel.

Sol PurposeThe total time to complete this project was around 4 weeks where I worked on it most evenings where possible and each weekend.  Although the work was challenging, mainly due to space constraints and the unknown, I know have a full working knowledge of the setup in my boat which will make any future troubleshooting that much easier.

This May we took the boat offshore for a trip to the border of Mexico which had us offshore for three and a half days.  We ran the autopilot continuously and it complained once that it wanted the rudder recalibrated which we ignored and it went on performing without issue.


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