Autopilot

Mario · Post by **Mario** » Wed 09 Jun 10, 8:58

Autopilot stopped working. I examined all instruments, excluded ”software” problems, and found that the drive unit was not responding. Expecting that a fuse had blown I started searching for fuse placement. It appears that the fuse is placed inside the Jefa drive unit box. This box is placed under the deck of the cockpit behind the chain to the steering wheel. Not so easy access: With the head and nearly all my trunk down in the engine room I get close to the box and found entrance of wires. I had to screw up 4 small screws on the top cover. These screws needs a star screwdriver, and even I used the proper driver and handled with care, two of them broke (take care – stuff is really soft!). It was impossible to screw them up even I tried with different hard-metal tools. No way, I had to demount the entire autopilot drive unit – only 4 nuts… but on very, very long screws, where 2 of them are hidden behind the box = not visible. I demounted arms to the drive unit and with one (left) hand, the head and trunk down in the engine room slowly bit by bit I unscrewed all nuts. Despite that the unit is quite heavy it did not glide easily from screws because of very tight shock absorbing rubber tubes in box’s holes, so it required quite a lot of press to got it down. It took about 1½ hour of hard work in sweat. I got the animal out and was lucky to remove broken screws form the top cover without hammering and boring. The fuse is on the red wire just after it comes to the box. *@! can happens again, so I decided to move the fuse outside the box. Mounting the drive unit back on the place is much more challenging job: through the entrance to the engine room, with your left hand under the cockpit deck you have to lift this heavy box up towards screws on the roof of the cockpit, align them properly, press so hard that the rubber tubes will “glide” on screws and then, with the same (left) hand screw nuts on. Well, good luck! I used wooden wedges under the box to lift it gradually up and after 1 hour work the unit was on place with nuts on. Then, only replacement of the arms and finale grande!
Other methods of access for replacing this fuse: Remove the wall between engine room and cabin, and do it from the cabin site; or: remove Volvo engine out of the room and turn the boat upside-down…
To those who order a new 35’er: order Jefa autopilot drive unit with the fuse outside the box – in such case exchanging the fuse will take less than 1 minute.
Sunny and windy summer,
Mario
Please click on any of the photos to see them enlarged!

Photo 1: Jefa autopilot drive unit hidden under the cockpit deck
Photo 2: Top cover of the drive unit where the fuse is placed (screws are already replaced)
Photo 3: Fuse prepared for mounting outside the box

Oscar · Post by **Oscar** » Sun 13 Jun 10, 0:13

I guess you don't have access to a mechanically inclined chimpanzee.....

I always try and install things so you can get to them. Imagine doing what you just did on a solo trip off shore when you NEED the autopilot....

Mario · Post by **Mario** » Sun 13 Jun 10, 6:20

That’s also my point. It can be very serious problem.
Bo, if the problems with exchanging autopilots fuse concern not only 35’er owners, will it be an idea to move this topic to general section for all users?

Post by **Bo Wetzel** » Sun 13 Jun 10, 8:36

Mario, I don't think it's the same on other boats. Certainly not on DF25, DF800, DF920, DF28.
So, best to leave this topic where it is.

Gonzo · Post by **Gonzo** » Wed 30 Jun 10, 13:51

We had the same problem with the autopilot while doing the 2 handed Shetland Round Britain and Ireland race. I checked all the fuses I could find and they were ok, looking at the Wiring diagrams didn't help at all. A phone call to the Dragonfly Agent didn't get any useful advice on this although he was very helpful on other matters.
I reckoned it was probably a fuse on the drive as we had other electrical issues as well ( I'll put them in another thread ).
I tried getting at the drive unit in the engine compartment but I'm not the skinniest of people.
The problem started approaching the Shetland Islands and we ended up having to manually steer the remaining 800+ miles to Plymouth. We haven't got the boat back to its home port yet but will readdress the problem then.
cheers
Gonzo
co-skipper/crew/cook - Cold Fusion Reloaded - DF 35 no. 28

Double Horizon · Post by **Double Horizon** » Wed 30 Jun 10, 14:33

Mario in your middle picture it looks like there are red and black wires running to the same post. That is very confusing. Can you provide more info about that?

Mario · Post by **Mario** » Wed 30 Jun 10, 21:08

Larry, yes, two thickest of the them are red for + and black for –, the thinnest two are… well..., how to say it…, to be honest…, I don’t know…, but must be data wires.
Gonzo, first of all congratulation on your race! I followed your trip with interest, and would love to here more about it. Hope you will write a bit. Regarding the fuse: Come to Cph and I will fix it for you.
Mario

Einar Gloersen · Post by **Einar Gloersen** » Fri 22 Oct 10, 0:22

Just for your information, the two thinner wires are for the clutch. I just bought the autopilot from Jefa, and on this one the fuse is mountet on the wire and not inside the autopilot. By the way Mario, thank you for the pictures, makes it simpler for me I hope, to mount the autopilot. Do you think a car jack could be used to lift the autopilot into position?

Mario · Post by **Mario** » Sat 23 Oct 10, 22:10

Well, standard car jack will still require two hands and has small contact surface, so it can be difficult to hold this heavy box on place (at the beginning at least). But you can try. My job was very easy: take it down and than just up to the same place- on the same screws. You know, my screws are originally mounted- laminated fast to the roof. I understand that you have to install all the new system, i.e. start with mounting 4 screws first. But it can be that you can use self-expanding screw system, so you will get kind of nuts in the roof wall, and than, you can use screws to mount the box.
Einar, if you gonna do itself I can send you more photos.
Gonzo, have you fixed your problem? Or… can I expect you in Cph next summer

?

Einar Gloersen · Post by **Einar Gloersen** » Sun 01 May 11, 22:58

Mario, the autopilot is now mounted, used the method you described. The frame for mounting the autopilot was already in place, and inserting the 4 pin bolts was just a little difficult.
According to the Jefa manual the torque for the fastening of the autopilot should be 3Nm, so that the shock absorbing rubber tubes are not damaged. How it should be possible to mount the autopilot with this low force is beyond me, unless you position the boat upside down, but I suppose loosening the nuts a little after the autopilot is in position should be sufficient.