Autopilot Upgrade - Wiring the System

Upgrading the Autopilot Power supply

Our existing Autopilot was badly wired when installed before we purchased the boat Six years ago. Now that we're replacing the Autopilot with a new Raymarine EV-100 system, we're making sure that the power supply is up to spec, all of the other cables are new.

The Autopilot Control Unit (ACU-100), the Electronics and Wheel drive motor of the system, requires 7amps 12v DC power. Separately, the new Raymarine SeaTalkng network Backbone requires 3 to 5 amps. 

The Electrical Control panel on Eximius is planned to be rewired later this year but we'll take any opportunity to upgrade the electrical system before then.

The Electrical Control panel has a 15amp breaker for the Autopilot. With a total of a max of 7amps, I'll replace existing 15amp breaker with a 10amp breaker.

The existing wire from the breaker to the Autopilot is #16 and the round trip distance is about 30 to 40 feet. The Correct wire size for 7 amps along that length of wire is #10.

Of course, the probability is that the -ve cable to the old Autopilot is also a #16 so that will have to be changed out for a #10 also. I installed a -ve Bus Bar adjacent to the engine a couple of  years ago, however, the planned upgrade to the Electrical panel includes having new -ve bus bars inside of the electrical panel housing. There is a -ve bus bar in that area, but it's just not suitable - and has far to many wires terminated at the bus bar. I'll install a temporary -ve Bus Bar near the panel.

So, we're going to pull two Red #10 (+ve) and a Yellow #10 (-ve) wires from behind the Electrical panel, aft into the Bathroom, aft again into the area behind the aft berth stern bulkhead then to the ACU area along with all of the other wires from the Navigation system (GPS, NEMA2000, Radar, and VHF, Echo Depth Instrument). 

In an earlier post I covered the rewiring of the instruments at the Helm Nav Shelf, so all of the instrument cables now exit from the deck down into the aft berth.

The existing electronics requires 2 fused connections supplied via the Aux GPS Circuit Breaker. Another two fused connections to be supplied via the Autopilot Circuit Breaker.

I have just ordered a second fuse block (see below) in order to provide a neat install of all four of those connections.

These blocks have a transparent cover and have 4 individually fused connections, however, I expect that only two of each will be required.

There will be a seperate Terminal block for the -ve connections.

Those fuse blocks will be mounted on the Aft Bulkhead close to the ACU. 

RANT Time!

Ok, I understand that electronics manufacturers need to make the cables long enough to suite a wide variety of installations, so the cables can be quite a bit longer than required. HOWEVER - they should have a note on the installation instructions suggesting that the cables should be trimmed to a length suitable for the installation. I've seen so many installs of Boat Electronics where the installer has coiled up the wires and left them loafing about somewhere behind the various panels on the boat. Today I pulled out 6 cables each one at least 15' long that could have been as short as 5' Grrrrr! I spent over an hour figuring out which cables were no longer required and could be removed in their entirety. At least I got them all out.    But then I started on replacing the power wires for both the Garmin Echo depth finder and the Garmin GPS - I knew they were bad, but had no idea how bad! Tomorrow I'll work on replacing those cables.

RANT Off!

During a conversation with the Raymaine Tech support, I learned that there should only be a single power connection to the SeaTalkng Network backbone. My plan was to add 12v DC to that backbone. However, as they also clarified that the SeaTalkng backbone is basically identical in function to the NEMA 2000 backbone and that if they are going to be connected it should be via a SeaTalkng to NEMA 2000 (which Raymarine refer to as 'Device net') via a backbone connection and not a spur connection. That means that the 12v DC that is already provided for the NMEA 2000 network will also power the SeaTalkng backbone. One less power supply to worry about. That means that the 2nd Fuse block noted above will only provide power to the ACU-100 and not to the SeaTalkng backbone.

Down at the boat yesterday, I was able to remove a few unwanted cables (because they went nowhere and had no power on them). It required that I remove the Aft Bulkhead in the Aft Cabin, not too difficult. The port side bulkhead of the Aft Cabin also came out just to allow more access.

It will take a bit of effort to sort out the remaining cables. The Data cable from the Radar Unit cannot be cut and has about 30' of excess cable. Probably because the Radar Dome has the option to be mounted up the mast.

The bare wire connections that have to be made to the ACU-100 are the type I try to avoid, but there's no getting around it on this device. However, I can terminate the bare wire ends with Ferrules.

The ends of the bare wires that extend beyond the ferrules will be cut off. That leaves a nice and strong termination to clamp down with the Screw in wire holders of the ACU-100

Those ferrules will be used on the bare wire ends of connections for the SeaTalkng Spur cable, the Wheel Motor Power, the Rudder Position Sensor and the Power cables.

Some of those wires are just 24awg, imagine how fragile they would be if the bare wire ends were simply inserted and screwed down into place.  The kit was cheap from Amazon, worth every penny.

The old power cable for the old Autopilot is a two wire sleeved cable at the Autopilot end, but the other end is not sleeved and is not the same cable. So that whole wire has to come out as mentioned above. Sadly, the cable passes from behind that aft panel in the Aft Cabin up to the side of the Port side Cockpit locker - that means the locker has to be emptied - it's crammed! Probability is that I'll find a join in the cable that is slavered in liquid tape - I really really detest that stuff.

Anyway, while getting this part of the project done, Peggy found another leak in the cockpit, she was scrubbing it down after all the groty work I did earlier this week. The to Aft Cabin port lights are leaking. Another project, but for now I have applied Butyl Tape to where the outside port light flange attaches to the side of the cockpit seating. Another post for that.

At this point we're ready to run the power cables, 30 mins to empty the port side cockpit locker, another 30 to pull the old cable out (and the other defunct cables), same again to the the cables all the way from the 12v Control panel. Replacement should be  quicker as there'll be room in the loom cable ties for the new cables after pulling out all of the old cables.

That's Monday's job.

This project does seem to be taking a whole lot longer than expected, what's unusual about that, but we are spending time getting rid of the failed equipment and wiring. If we were installing this from scratch it would take a fraction of this time.  Oh well! Boat projects tend to do that.

Update: Here's the schematic modified after talking with Raymarine Support

Had to take a break on this as we found a couple of leaky leaky bits around the cockpit to aft cabin windows, that lost us two days.

Back on task, I removed the wooden bulkhead between the aft berth and the fuel tank in addition to the bulkhead between the aft berth and the water tank, all in order to get access to the jumble of wires that are behind those panels. So far I have pulled out another 40' of poor quality wire, bad connections and wrong sized wires.  By Saturday we had the wires pulled all the way into the main salon, just a couple more feet to go in order to get them out from the tangle of wiring behind the electrical panel. See the pic at the top of this post.

It's Labor Day Weekend, so we're doing family stuff until Tuesday, plus I'll get a bit of Canvas work done to bring in some boat bucks. Plan is to head down to the boat on Tuesday morning with the hope of running the new wiring from the circuit breakers to the fuse blocks close to the ACU and the GPS/Echo instruments.

Just in case you're wondering! Yes, we're ready to get the boat out as soon as this work is done! Working on the boat is fun and fulfilling, but we need water under the keel time.

Update Thursday Sept. 9th.

Down at the boat yesterday. Peggy spent most of the morning scrubbing down the deck, it's a constant challenge. With the power cables ran from the Cabin thru to the After berth, I was able to sort out the mess of wiring above the aft water tank. While at it (yep, another bit of project creep) I pulled the wire for the Echo Depth finder's transponder from it's old route into a much shorter and neater route which allowed for the additional wire to be coiled up neatly. Here's a pic of the current state of the wiring behind the aft bulkhead.

NEW PIC HERE

Sadly I could not find the adapter cable I had purchased from Amazon that joins the NEMA 2000 backbone to the SeaTalkng backbone - we spent way too much time searching for it. A new cable should arrive Friday. Saturday we'll go down to the boat and should complete the wiring at the Aft bulkhead, connecting the ACU and the Backbones. That should leave just a few more steps.

• Replace the Wheel Pilot with the new one.
• Complete the cable management of the wiring from the aft berth all the way to the main cabin.
• Connect the Positives (Red #10) to the two circuit breakers
• Connect the two Negatives (Yellow #10) to the -ne Bus bar at the back of the electrical control panel.
• Test everything before doing the sea trials.

Well, Saturday was a huge success. I completed the looming of the cables in the Port Side Cockpit locker, removing about 30 old zip ties that were really not doing anything. Then completed the wiring in the aft berth, that's the cables going to the ACU, the SeaTalkng backbone connection to the NEMA 2000 backbone. Installed the Negative terminal block and connected the -ve from the ACU power connection, the -ve from the Echo depth instrument and the -ve from the GPS power connection. Then the +ves to the two fuse blocks  - 1 for the ACU and the other for the GPS & Echo Depth. Ran the ground wire from the ACU to the fuel tank grounding tag (the fuel tank is grounded to the engine) Basically got all of the wiring in the aft berth complete.

So the plan on Tuesday is to go down to the boat and run the wires from their entrance into the cabin (that's inside the sliding door cabinet above the Nav Station) and connect +v's and -v's as mentioned above, at that point we should be able to test the electronics. WooHoo!

Of course, life gets in the way! On monday the roofing company is due to arrive at our home to start work on replacing the roof and Facia. We're in Florida, so that work needs a bit of personal supervision, the last company we used 20 years ago did a carp job and had to re-do some of it due to failing an inspection. Now I know what to look for - and I'll be looking!

We may get the boat out in a week or so, won't that be sweet!

See you on the water - soon.