Catalina 34 Fluxgate Compass Location

[DEMERY]

I have a 1990 Catalina 34 with a Raymaine ST4000 Autopilot. I recently upgraded my electrical system to include 4 6-volt batteries (in the existing battery compartment), a separate starting battery (located forward of the starboard water tank), larger battery cables and a 75-amp high output alternator. I immediately began to experience autopilot problems (unable to hold a course) when the batteries are being charged. My fluxgate compass is currently located in the second bilge compartment next to the battery compartment and cables. I believe my problems are related to the magnetic field being generated from the cables or batteries while they’re being charged. I’m looking for advice as to where to move the fluxgate compass. Where is Catalina currently installing the compass on new 34’s? Has anyone experienced this problem, and where did you relocate your fluxgate compass.

Thanks, Dave

[Roc]

Dave,
I have a 2000 mkII model.  Mine came with factory installed autopilot (actually installed through Ocean Equipment, who seems to be contracted by Catalina).  They put the compass under the port side settee on the bulk head that separates the holding tank area and the storage area.  It's near the macerator and at first I thought that would be a problem, but I see no issue with holding a course.

Roc-

[rdavison]

Dave,
I have a Mark I and went down exactly the same road.  I patched in a few feet of extra wire and moved the compass forward to the first bulkhead aft of the mast base - can't remember if that was one or two forward.  It solved the problem completely.

I don't remember how many strands are in the fluxgate wire or whether it's shielded.  I just cut it and then bought something similar.  Remember that the bilge is a very bad place for sensitive wiring.  I sealed the connections very well and then tie wrapped the extension to the bundle of wires running forward to keep it well away from water in the bilge.

Randy Davison  #1268 1993 k7voe

[mvazmina]

I have an older model #27 and the unit is installed under the sink right behind the drawer with access from the side door on the gally counter. I have not had any problems with that proximity to the batteries

[Jentine]

I have a very sensitive instrument that detects magnetism of very minute proportions and found the best place (the one with the least magnetism) to be below the chest of drawers in the V-berth on the port side.  I have a mark one like you.
Jim Kane :)

[s michel]

We found that we had a replaced cable in the helm which was magnetic(stainless).Replaced it and moved the fluxgate to new location on the aft bulkhead about 6" off of centerline to port side.
It has worked flawlessly now for 18 months.

Probably the best money spent on this boat.!!!

[c34member]

Mine is mounted below the rear berth down in the  bin frame portion of the (head) bulkhead beside the lift muffler.  The only problem I have is a 5 degree variation when the motor & blower are operating.

It's on my to-do list to re-route the blower wires or move the compass.

[Stu Jackson]

Dave

I assume you have also used the Message Board and C34 website Search Engines in your quest.  Lots of material already posted.

Stu

[Fulvio]

... since nobody else seems to have the fluxgate in this location, I'll chip in:
mine is in the aft cabin, mounted on the forward side of the aft bulkhead, exactly on the centerline.  It's about 4 inches above the mattress, but it's never bothered me, and I've never had any problems holding the course.

Fulvio Casali
Seattle WA
Soliton
#929 (1989)

[Norris Johnson]

Mine is installed on the same bulkhead as #929, but under the mattress and I have a huge snake-wake under sail or power. I think I will move mine foward to the holding tank compartment where Catalina installs them.

Norris Johnson
Mariposa
#1408

[Fulvio]

Keep in mind that the autohelm control head has a dozen different calibration settings, some of which are sure to affect the "snaking" behavior.  I had seen the calibration section in the manual, but it wasn't until I actually had to re-install the wheel drive unit that I discovered how many individual settings there are.

Fulvio Casali
Seattle WA
Soliton
#929 (1989)

[Norris Johnson]

You're right, Fulvio. I've tried combinations from this web site and others. The best one for me came from this web site last year. I'm just going to go with what Catalina does from the factory. It's not too difficult to do. I have plenty of wire.

What a great website!

[Gary Wilson]

I can weigh in on the battery compartment being a problem location.  Mine is on the outside of the compartment, with the wire running into, then out of the battery compartment right along with all of the battery cables.  It works fine except when a motor is turned on, like the macerator or water pump or bilge pump.  Then, the helm turns hard over.
     Too bad the location instructions from the factory did not caution against proximity to the bateries.