Where to start looking for the Autopilot Compass on a 43 DC?

[Vincentc]

Lilly Marie's autopilot stopped working. It is a Navico Corus 1995 or so vintage, so it was installed over 10 years after the boat was built.

The Control unit (C600AD) at the helm no longer shows the compass heading so I suspect there is a problem with the (ATC600) Compass. The AP Computer (OCC1) is located in the master stateroom forward closet and the wires to it are bundled giving no hint where they put the compass.

Any experience regarding likely locations for the ap compass on a 43DC or thoughts regarding the cause of this problem will be appreciated.

Regards,

 

[bobk]

Vincent, No experience with the 43, but most aftermarket stull can vary. Look low and near centerline, hopefully close to midship and away from other motors and large iron masses. I found mine on the 48MY under the locker under the lower mid ship bunk.

bobk

 

[Timeout]

I placed my new one in the forward closet up high in the master stateroom. Found an old disfunctional one under the bridge cowl and another old one on the back bulkhead up high in the engine room.

 

[eze2bme]

The AP compass on my 1979 is located in the linen closet in the aft head underneath the lowest shelf. You'll have to get on your knees to see it. Hope this helps.

 

[lumina]

Hi All,

I found mine in the bottom cupboard under the dresser drawers in the mid stateroom of my 48 YF. It was right next to a big heavy steel box. go figure !!

 

[Bob Bradley]

On my 43C '79 it was in the space under the master berth.

 

[Canuck Dennis]

Ditto as per Bob, mine is just behind the aft fuel tank ahead of the rudders.

 

[Vincentc]

It has been a long time since I hunted for Easter Eggs, but not that long since I hid them. This all sounds kind of familiar.

Thanks for the hints.

If, when, I find it I will let you know where they hid it.

Regards,

 

[Will]

We have a Robertson 22 auto pilot with the control unit mounted in the centerline master stateroom hanging locker on the bottom of the access door to the back of the midship electrical panels. the sensor itself is located under the aftermost port side M.E. muffler just aft of the port side locker in the master stateroom.
Will 1980 43' DC.

 

[bostonhatteras]

Follow the cable from the Control Panel. You must be able to see the autopilot "brain". Look to see what terminals are for the compass and trace that cable to where the compass is.

 

[Vincentc]

Follow the cable from the Control Panel. You must be able to see the autopilot "brain". Look to see what terminals are for the compass and trace that cable to where the compass is.

That makes perfect sense, I already tried that; however, none of the wire connection on the ap computer are labeled compass and the manual does not add any clarification.

Good thought.

 

[bostonhatteras]

The installation manual sure will. What are you running? If its Robertson ap 20 series I believe they all install the same. I will look at the book next time I'm at the boat in a day or so.

 

[bobk]

Would a signal generator help with tracing the wires or would that be risky on a compass?

Bobk

 

[bostonhatteras]

Would a signal generator help with tracing the wires or would that be risky on a compass?

Bobk

I think that's not a good idea.

Here's a link to the full manual.
http://www.simrad-yachting.com/Root/Operator Manual/SimradYachting/English/20220596H_AP21_22.pdf

There are a couple installation options depending on junction box and whether you have a rate compass or regular fluxgate. Look at the manual. It should be self explanatory then. Good luck.

 

[Vincentc]

Thanks for the input; however, No luck so far. My son and I looked at and tried to follow wires for about an hour, and all we found was frustration.

The manuals tell you where you should put the compass, but not where the installer did put it.

With some confidence I can saw where it is not.

The only wire leading aft goes to the rudder indicator.

One of the wires goes to a network junction box next to the ap computer. Two wires connected to the computer carry power, one to the computer, and the other carries power to the ap hydraulic pump in the engine room.

There are four other wires, not accounted for. They all go up and to stbd. I checked all the wires inside the column wire chase next to the helm. With me pulling on each wire and my son watching the wires at the computer, none moved, telling me the compass is not on the fly bridge .

We likewise checked all wires accessible from the access panel in the saloon below the helm instrument panel.
Nothing.

All possible wires go into the rabbit hole above the closet and stbd of the electric panel under the stairs from the saloon to the aft deck. Where the go from there is a mystery. I found nothing in the storage area stbd of the helm and nothing in the master head closets.

Any more thoughts?

 

[Timeout]

Can you take off the panel below the access panel behind the helm? I have a mirror there which when removed allows me to remove a very large panel. Maybe its down lower in that same area.

 

[Boatnut]

Hi Vincent,

Remembering way back, I help a friend install a Navico autopilot. The unit we installed did not use an external compass, it had a built in flux gate compass. The external compass was an option. Some say an external compass works best. My B&G autopilot has a built in compass and no external one, and the unit has work flawlessly for 15 years. It kind of makes me wonder if you may be looking for something that is not there. You could open up the unit, and see if there is a compass inside. They look like a little gyro.

Good luck.

 

[bostonhatteras]

The manuals tell you where you should put the compass, but not where the installer did put it.



Any more thoughts?[/QUOTE
The manual tells you how to wire it in and where to put it! First off we need to confirm what brand of ap you are dealing with. I'm assuming you have a simrad ap 22. If that isn't the case then what I'm saying may not apply. They all aren't the same as the other posters have alluded to. If it is a ap 22 then there can only be two places that the compass is wired in. It is either installed with a plug in connector with threaded collar on the back of the control head or the screw down type connector was cut off and it was wired directly to the junction box. The nomenclature for the ap 22 is that the main computer is called the junction box. They aren't using that term as an electrician would. Also simrad does not call out any additional terminal connections aside from the home runs of: 1 power to the junction box, 2 power from junction box to hydraulic pump, 3 rudder feed back, 4 control head, 5 compass. You could have additional wires for communication between ap and GPS or chartplotter but I don't want to confuse the issue. With the exception of the compass these should all be continuous runs directly to and from the individual components. They cannot be shared with anything else and should be electrically shielded from other wires especially the compass and rudder feed back. Regardless of what the original installer did, if you can find the junction box (where wires are terminated on a long strip with screw down wire clamps and it has circuit boards and it shape is probably 11"x9"x2" and black) then you can follow every wire away from that. If the compass isn't wired in there then the only other place it can be is connected into the back of the control head. That's all true if its an ap 22.

 

[Boatnut]

Lilly Marie's autopilot stopped working. It is a Navico Corus 1995 or so vintage, so it was installed over 10 years after the boat was built.

The Control unit (C600AD) at the helm no longer shows the compass heading so I suspect there is a problem with the (ATC600) Compass. The AP Computer (OCC1) is located in the master stateroom forward closet and the wires to it are bundled giving no hint where they put the compass.

Any experience regarding likely locations for the ap compass on a 43DC or thoughts regarding the cause of this problem will be appreciated.

Regards,

Obviously it's not an ap 22 The info I was able to find listed the navico as a one piece unit, which suggests to me there may not be an external compass. It appears the color of the wires to the compass, are white and green.

 

[Vincentc]

I have looked at the manual and the computer in the closet and am convinced there is not a compass inside the computer.

Discussion and consideration led me to realize that Last night's search ignored the possibility that the compass is wired to the control head next to the helm and not directly to the computer in the closet. The control head is mounted to the bulkhead with no visible mounting screws. The manual provides no help regarding how the panel is mounted, hope I don't break anything trying to get to the mounting screws.

Thanks