Sunday, September 1, 2013

The Illustrated Garmin DIY Auto Pilot Installation

It's a "Green Field" autopilot install. By that I mean I'm dealing with a new boat. I've also been waiting for a while to find a boat with little infrastructure, and design forethought for an autopilot. This will allow me to talk a bit about some of the tribulations you can encounter, and what the options are to solve them. At some point I will ask that the Garmin and Teleflex people to leave the room briefly, while I read from the Installer's sacred text titled "In the Real World." The goal is to make you feel good about your chances of installing one of these systems, and have it work, ahem, the first time.

As my colleague Jay Sellers used to say, "Here is my office today." The good news is it's clean, and has room for me. The bad news it's steam room hot, there is little room to install things, and the dealership has already installed a chart plotter, radar, stereo, and other odds and ends.

There is even disco style multicolored LED lighting system installed under the cockpit coamings with a Bluetooth link to the Fusion stereo. By playing Led Zeppelin, you can scare the fish to the surface, and cause epileptic fits in the crew. The point is that all the power available has been jumpered off the console switch panel, and I need a bunch more. So lets start with autopilot power needs.

Regardless of autopilot system you install, they all need a fair amount of power. You're going to run a substantial DC powered hydraulic pump and this isn't the place to be chintzy with Mr. Electricity. In the case of the Garmin GHP 10, it's the ECU (Electronic Control Unit) that drives the pump, and it's fused at 40 amps. The control head, and other bits only use a wee bit of current. This boat has no power or ground strip, so we have to start from scratch to install a fuse block.

The distance between the battery switch and console is 8', so let's just say 10' so it fits the tables. Tables you say? Yep, I need to know what size wire I need to carry 40 amps the ten feet. Two tables exist in the link. One is for a 3% voltage loss, and the other is for a 10% loss. In this case I'm using #10 wire. It's a slight overkill, and the extra power may be desired later.

Lets check on what we bought, or in this case what the dealership bought. We have a 2.1L pump, and a Garmin GHP 10 autopilot system. We now have everything we need down to the screws to install the system except for the hydraulic plumbing pieces. We will do that messy job last.

We have a string of things that have to find a home. I'll start first with the twins. The pump, which only has about 19" of cables and the ECU it has to plug into. In sum they must be very close to each other. In this case there is only one real option. The side ledges in the console aren't wide enough, so where you see it, is where it goes. That hatch below it will now be blocked. It's the access to the the gas tank sender and hoses. Pull four screws, move the pump, and you can get to it. It was the best of the very limited options.

The CCU (Course Computer Unit) is also in a " It's the best we can do place", and it will be okay." This unit also includes the heading compass. I mounted it on the front of the console interior directly behind the forward facing seat back. This allows me to screw it in, and the small amount of screw tip protuberance ends up in the black starboard esque backing of the seat back.

I need to be at least a good yard from any ferrous metals (anything a magnet will stick to). Ideally you would want the compass at the waterline on or near the center of the longitudinal axis of the boat. But good luck with that on most boats. I can't get this CCU any lower because there is a water pump in an inconvenient location below the the unit.

I used the existing bolts with screw hole tie wraps to secure the wires. The wire bundle leaving the CCU is a NMEA 2000 cable, and a split cable. The split cable end with the connector will go to the ECU, and the one with a bunch of tiny colorful wires will need to be connected to other devices. For the time being we will just get it to the fuse block.

The last major piece of gear you need to install is the GHC 10 autopilot head. Just take your 3 and 17/32" sized hole saw and punch a hole in the dash. If you don't happen to have that sized hole saw, then just use your convenient 90mm hole saw. What you don't have one of those either? Not to worry, it's close to 3 1/2 inches, and you can try that hole saw.

By the way, 90mm is actually 3.5433". I haven't actually tried a 3 1/2" hole saw with this specific unit, but I have tried it when 90mm holes been specified by other manufacturers, and it's almost as large as it needs to be, and yet just not quite. Out comes tools, sandpaper and appropriate expletives. So in the end, I tape on the template, and use a Rotozip to cut the hole removing all of the template cut out line. This gives me some adjustment wiggle room for tight fits. Okay this is pretty much the end of the power tool stuff, now for the wiring.

We have to build a NEMA 2000 network to connect the CCU to the GHC 10 autopilot head. If you're doing a stand alone system, the picture above is what it should look like, and all of the pieces are included with the system. If you have an existing Garmin NMEA 2000 network, remove the tee and it's associated yellow power wire, and connect the two other tee's into the existing system. The two NMEA cables are six feet long. If your CCU is further away than that, and on larger boats this is very likely, you will need to buy a longer cable. 

There are several more wiring connections that need to be made, and we will deal with autopilot head first. We have two plugs on the back. One is the NMEA 2000 plug we just talked about, and the other is the power cord sort of.

The original GHC 10's used the cord for actual power, but the current version gets its power from the NMEA network. We still need the cable, so plug it in, and get it to the fuse block. My general approach is to try to get the CCU cable with all of the small wires near the fuse block so its close to the GHC 10 power cable, and all of the interface connections are made in one place.

Most of these are straight forward connections Make sure you have connected the CCU yellow wire to the GHC 10's power cable yellow wire. The system will not turn on if this connection is not made. The GHC 10's black wire must go the ships ground.

The Tach connections can in some cases be a bit inscrutable. The tach inputs come from the grey sender wires on the back of analog tachs. It is not a guarantee that every tach signal can be used. If you have triple or quadruple engines use only the two outboard engines. In this case I have a single 300HP 4 stroke Yamaha, with digital tachs. In order to get tach data to the system I have to add a Yamaha NMEA 2000 gateway which I have no instructions to provide. 

Now for the big ugly, plumbing the hydraulics. You will need a couple of plastic bottles, lots of rags, a roll of paper towels and the toolbox with all of the wrenches. Wear old clothes, this is not the place for your nice Columbia fishing shirt. The Garmin and Teleflex kids can now take their lunch break during this session.

In this case we are plumbing the latest generation 2.1 liter pump. I'm not going to talk about pump selection today. It can be complicated, and full of nuance. My general rule of thumb is to be conservative in sizing, and talk with the equipment vendor about your boat before you purchase the pump.

The are two versions of plumbing for this pump. This is the 5 port, four hose version. According to tech support this is a viable plumbing option, but if something happens to the hydraulic manifold block, the boat would be devoid of steering. This is a possible, but in my opinion not a likely scenario, and I have never seen it happen.

I have used this configuration in the past many times without problems, but I don't completely disregard input from tech support. In this case I didn't use this scenario, although it costs less to install. I will pursue this discussion further with them.

The next version is the 3 port 9 hose three valve scenario. It almost takes my breath away just to say it. I used a variant of this layout that skips the valves, removes 3 hoses and a bunch of fittings for this job. The 2.1L pump instruction manual from just a couple of years ago had no valves shown.

The argument I was given was the addition of the valves allows the pump to be removed with minimal fluid loss. You are also guaranteed the ability to steer the boat regardless of what's happening with the pump. My thoughts are on smaller boats, it's costly, and creates additional plumbing in already often very confined areas. But on larger boats with miles of hydraulic hoses/tubing it would pay off. This boat is a 24' center console, and a quart of steering juice, and a empty Gatorade bottle will take care of any repair issues.

Getting hosed is what happens if you don't have time to plan ahead, and in this case I didn't. I was told a day before about the job, and the boat needed to be delivered soonest. Hoses are always an issue. The shorter lengths are never in stock at my big box retailer, although they were in the warehouse, and I could get them in a day, at a price of about $90 a pair. Pairs are what they are always sold in, and I needed five. I happen to have an extra hose left over from another job. This was good, because there wasn't a third set in the warehouse.

The option I would have preferred to use is the Teleflex HT5092 3/8 nylon tubing. This item is never stocked in the big box marine warehouse, although I think it should be if you're in the business of selling autopilots.

You can get 25' online for about $60.00. There is little waste, and it's easy to use, albeit it's stiff, and has a larger bending radius than the hose. In this scenario there was not enough time to buy and ship the stuff. I did have enough tubing to use for the return line, saving some bucks on the job. The box of tubing I ordered came in four days later. You can buy a nifty tubing cutter for about $10.00 saving you from the eventuality of stitches when using a utility knife to cut the tubing. It's very tough stuff.

You have to get all of these pieces connected, and here are the parts you will most likely use.

Number 1 is a compression tube nut for the 3/8" nylon tubing if used. Number 2 is a 1/4" NPT thread on one end, and 3/8 thread on the other end. You can use tube nuts, or regular Teleflex hose fittings on the 3/8 side. Number 3 is a ninety degree version of number 2. Number 4 is a tee that is 3/8 threaded on all three ends. Five is a version of four with one end having 1/4 NPT threads. And six is five with the NPT threads on the tee. Add to this various 1/4 NPT nipples and couplers as needed to make things work. Again, these will not typically be on the shelf of your local marine retailer, but in my case there is a hydraulic supply store in the area that stocks these pieces, and they are even less expensive on line. These little parts can be expensive. so figure out exactly what you need. I usually budget about $125.00 for parts needed for an install using the nylon 3/8 tubing.

The hydraulic cut is the big ugly. There is an order to all of this. Prep the pump, and shadow drive with any required #2, or #3 fittings. Garmin supplies a handful of #2 fittings with the pump. All 1/4 inch NPT fittings need sealant on them. You can see my discussion about what to use here. Next decide on where the shadow drive is going to go. It has to be horizontal. There is a little shuttle inside of it, that detects fluid motion. Have all of your tools and parts handy. Also this is the time for the rags, and collection bottle. A wide mouth Gatorade bottle works. well. We also want to have a #3 (mostly) or a #1 fitting (on occasion) ready to go with sealant on it for the return line.

Were going to first remove the filler cap for the helm up on the dash, then open the port at the six o'clock position. I pointed to it in a pic earlier. Opening this will drain the helm reservoir. Loosen it with a wrench enough so you can turn it by hand. Quickly remove it and get the bottle under it. In a couple of minutes it will just be dripping a bit. Pull the bottle, leave rags to collect the few remaining drips and screw in the hose fitting.

Now a note of caution about the two existing hoses. These are port and starboard connected. If you flip them the steering will be backward much to the drivers distress so pay attention to what is going where.

I have a delay in my process because someone at the factory decided it would be a good idea to play it safe, and put pipe thread goo in the 3/8 fittings. This was not a good thing to do. These hose fittings are compression by nature, and do not require sealants. They used copious quantities, and it took me about thirty minutes to get most of this stuff cleaned out of the threads.

Where was I? Oh yeah, take off one of the two hoses from the helm. It doesn't matter which one. Hold it higher than the pump while you collect the fluid from the port with the plastic bottle. When it goes to an occasional drip, take the end of the hose you removed, and stick it into the bottle, and you can then lower the hose, and let some of the liquid drain out. Use a tie wrap to hang the hose up high enough so it won't drip. Don't touch the helm, or you will spurt more steering fluid out.

Now it becomes mechanical. Attach a new hose to the now empty helm port, and then screw the shadow drive into the other end. Attach another new hose to the other end of the shadow drive, and in this case put a #4 tee at the other end. Then take the hose you removed and hung up, and attach it to the other end of the tee. Now repeat this for the other side, you just don't have a shadow drive, and one less hose. If you do it in this order you won't screw up the port and starboard sides.

Three hoses to go. Run a hose from the six o'clock port (the one you opened first), and connect it to the return port on the pump. Use the last two hoses to go from the tees, and connect them to the pump (H1 and H2 ports). When connecting them you don't have to worry about port or starboard sides. If they are backwards we will straighten them out with software during the set up.

You should now take a good look at your plumbing connections, and if all is good you can connect the yellow NMEA 2000 power cable, and the ECU power cable to the fuse block. Don't bother tying tie wrapping things yet. We have to purge, check for leaks, and general system operation.

It time to filler up, and purge. You have two choices, the first is SeaStar steering fluid. It's a bit pricey but when compared to the alternative ATF (Automatic Transmission Fluid) I'll take it any day. ATF although inexpensive has a distinctive red color, and if left on fiberglass for more than just a short period will stain. The SeaStar fluid is clear, and won't stain. The filler tube makes a tough job easy, so buy one when you pick up your hydraulic fluid.

Screw the small end in the helm filler port, and the other end into the SeaStar bottle. A small correction here. Bend the bottle end on the tube down, and rotate the bottle to screw in.

Now just tip the bottle up, and let the fluids flow. You will need to be able to see the outboard motor turn, and or the rudder arms move. If the rudder table is back in the lazarette you will need some one to yell at you with info about movement. Sometimes by opening an engine room hatch you can see the rudder table also. In all cases you need to know what's happening.

Start turning the helm in one direction for a bit at any rate. Fluid should be running into the helm from the bottle. Reverse direction and keep doing this back and forth. Eventually you should start to see rudder/motor movement, and the helm will come to a stop in each direction. When the helm stops, try to turn it a bit more, especially if seems to want to slip some in that direction. Don't do this in a roid raged kind of way. About this time, you should have seen bubbles escaping from the helm. Keep going back and forth until you get smooth motion in both directions, and not many bubbles. You're not done yet, turn the bottle back up and park it on the helm.

Push the on button on the GHC 10. It should turn on and have a message saying something to the tune of "searching for the autopilot controller." In a short period of time you should get a start-up display asking for language choice, units et al. When you're through answering the questions, the "Dockside Wizard" should appear. If it doesn't press the center menu button select "Setup", "Dealer Autopilot Configuration", "Wizards", and Dockside Wizard".

You have to fill in some blanks. The first is lock to lock turns. This is the number of 360 helm turns from port to starboard. Typically this is about 6 turns, but it can vary. The second blank is helm displacement. Most helms have a tag you can see. For most SeaStar helms this is either 1.7 or 2.4 cubic inches. If you don't know, don't guess, find out. 

Next is steering direction. The system asks you to push one of the two direction arrows and use it to move the motor/rudder. This is the time to see if you can purge the lines to the pump without manually bleeding the system. With the hydraulic bottle upside down again, try one direction for a couple of seconds. No motion, try the other direction. Usually in a few attempts back and forth you will get some motion in both directions, and you will be generally now be home free. Now check if the motor/rudder will turn you in the direction you asked it to go. If so, tell the system yes. If the motor/rudder is moving in the wrong direction say no. If it's a no, the system will ask you to move the motor/rudder again, and verify all is good. At this point you can now press the standby button, and you should get a standard heading display.

Take the hydraulic fluid bottle and flip it upside down again, while turning the helm port to starboard several times again. Now press "Auto" on the auto pilot control head and use the left and right dodge button to move the engine/rudders to almost full port to starboard, and then back the other way a few times until you get smooth motion both ways while keeping the fluid bottle upside down. Now repeat this with the helm a few times. If motion is now smooth in both directions, flip the bottle back up and park it. We will leave things like this overnight to let small entrained bubbles rise to the top. A quick cycle in the morning should get the rest of the air out. and you can then tie the hoses up, and clean up and residual fluids.

This cycle usually works well, but sometimes the purging can be cranky. It may be necessary in some cases to use the bleeder valve on the autopilot pump, and hand bleed the steering cylinder. My purging cycle worked well on this boat and was done in less that thirty minutes. Another ten minutes in the morning took care of the rest. Check carefully for leaks from time to time while you do the purging and tighten any leaking fittings.

You're done almost. Now do the Dockside Wizard again, and complete it while in the water. Go for a ride, and run the Sea Trial Wizard. You will need a good stretch of open water. The waters should be relatively calm and you don't want more than light winds. Follow the onscreen directions, and in about 30 minutes you really will be done. Don't take naps, or leave the helm while under auto pilot control, ever. 

Nuances and notes:

The Garmin GHP 10, and 2.1L pump instructions are clear, and understandable. Read them first before you start.

In the dockside set up, if you have no tach input, set this value to "None." For speed source, set to the correct value, ie GPS, or if there is no speed source, set to "None."

The 3/1/2" hole saw is not quite large enough for the GHC 10 cut out, and slightly enlarging it can be time consuming. For the cost of a good 90mm hole saw, you can buy a Rotozip.

A stand alone Garmin autopilot will require a NMEA 2000 marine updater to do software upgrades. The part number is 010-11480-00. These can be purchased on line for about $60.00. If you have a Garmin MFD connected to the auto pilot with NMEA 2000, you can use a SD card software update through the MFD.

Sharp eyes will see I used teflon tape. If the manufacturers find a wad of it in the helm, or pump they will be grumpy with you. I suspect that they would be just as grumpy with a ball of pipe thread paste found in the system also. Use your best judgement here.

I like the SeaStar nylon tubing, but it is not perfect for all applications. Long runs should be avoided because of its smaller internal diameter, and you should make sure the tube nuts are snugged down well to insure the tubing won't pop out. You will be able to tell it it's tight enough. That magic spot is when you think another 1/4" of movement will cause bad things to happen. That's when you stop.

Photos/Screen shots were borrowed from both Garmin, and SeaStar.


  1. Bill,
    what about installation in steel huls?

    I have instaled 10+ GHP-10 pilots in steel hulls diferent size and shapes. From my expirience best results are achieved when CCU is located in first third of the vessel as close to the water line as possible. I have in more than one instalation CCU bolted directly to steel bulkhead, as long as there is no changing source of magnetism nearby (removing toolbox, speaker, drawer sliedr etc...) everything works fine... Calibration on running water (river flow) is also not an issue, even that it is impossible to drive in circles (more in some strange kind of spirals...)

    Problems you have with 90mm hole drilling are of the same origin as the one we in have inland Europe with NPT hoses. No marine wholesellers here, and all hydraulics available are metric...

    Petar Maksimovic
    Belgrade, Serbia

  2. Hi,
    Recently got a new ecu to go with the 2.1L pump. It shows a red light in the middle and there is no action on the pump despite resetting the ghc 10 settings and trying to get it working. Any recommendations?
    Mombasa, Kenya.

  3. Mark, It's hard to tell with The info I have, but check these. I'm assuming you have Garmin MFD.

    Set the speed source of the GHC 10/20 to "GPS" in the set up.

    Make sure the yellow of the CCU harness is connected to the yellow of the GHC 10/20 and the black GHC 10/20 wire is connected to ground. In newer systems the GHC 10/20 gets its power from the N2K network and the red power lead is not used. So if its connected, disconnect it.

    I will need some additional details to go further.

  4. Is it acceptable to use the Seastar tubing with the compression nuts for all the hydraulic lines? Or is it wise to use hoses with crip-on fittings from Seastar to connect the autopilot pump to the helm?

  5. Anon, I have used the tubing for years to tee in autopilot pumps, but only the smaller ones like Ray's Type One and Garmin's 1.2L pumps. The tubing has a small ID and won't work well for the higher volume pumps and large displacement cylinders. As for helm (1.7 cubic inch) to cylinder runs in many cases you can use it, and in others such as specifically the Seastar HC5332 cylinder and for outboards they don't recommend its use. If in doubt contact Seastar for advice.

  6. I have a 34 foot silverton with a sea star BA135-7ATM 8.2 and I'm wondering what pump I should buy for the garmin ghp 10

  7. Any help would be greatly appreciated....I have a GHC 10 and I have an issue that I cannot get resolved. The helm will turn indefinitely and in order to keep the boat in a turn I need to continue to turn the helm or else the (twin honda 150 outboards will straighten). We have bled the system 4 times with no air in lines.

  8. CR, you have a check valve/fluid bypass thing happening. I'm not sure what kind of steering system you have but I'm guessing a Seastar. Check your plumbing layout again. My questions are:

    Are the steering cylinders balanced or unbalanced? The install instructions talk a bit about this.

    Is it possible something has gotten into the hydraulic fluid that is holding one of, or both of the helm pump check valves (small SS balls) open?

    Does this happen when you steer in both directions or just one?

    Have you check the steering cylinders for leaks coming from the ram seals?

  9. Hello I just installed a Garmin GHP Reactor Mechanical/Retrofit and a Octopus drive. I am having problems with the ECU giving me a error ECU high temperature. The ECU is mounted in my engine compartment it is not hot to the touch. I can not move it out because the cable that contacts the ECU to the drive is only about 2' long.
    Thanks Rick

  10. Still good info, thanks for the write up!


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