Autopilot affecting GPS

[Irish Mist]

Still getting used to the new boat and have an issue that I'm hoping is just an adjustment
When I first started using the boat All was good But now if I turn on the autopilot it turns the map on the GPS about 15 degrees Hoping someone else has experienced this and is just an adjustment.

Thank you

 

[Levitation]

I suspect electrical interference (RFI) is being generated by the autopilot - probably travelling on the power cables and getting into the MFD... Work on re-routing the power wires and control wires away from any wiring to/from the GPS - and vice versa.. Also route the GPS antenna coaxial cable as far from power wiring as possible..
My autopilot puts a signal on Channel 16 on my radio which forces me to change the channel or shut it off... Have not dug into that one yet bu t it is on my punch list...

 

[HRowland]

I believe the Garmin MFD will use the Autopilot CCU (Course Computer Unit) magnetic heading information when the Autopilot is powered on and GPS heading when the autopilot is off. The CCU is a round black ball shaped device. On my 27 it is located in the upper part of the cave behind the dinette seat. It might be aligned incorrectly (needs to be parallel to the keel) or need calibration. 15 degrees is also an interesting number, in my area of the Northeast this is also the magnetic variation between true and magnetic north. Not sure what the variation is for your area but something may be configured differently for true vs. magnetic north on the display.
Also check that you do not have a metal or magnetic object near the CCU. The CCU contains an electronic compass and is sensitive to magnetic fields.
Garmin also released a SW update not too long ago, one of the items mentioned in the notes is updated magnetic variation tables, but I would not expect this to be 15 degrees of error.

I need to go out on a calm day and perform some of the autopilot calibration routines, I have about a 10 degree error on my Garmin display. You can also see this in radar overlay mode, all radar returns are about 10 degrees off of the chart symbols. This is in the same direction all the time (plus or minus a few degrees) so it is not due to wind or current drift.

Howard

 

[Irish Mist]

Howard
Thanks you nailed it, I was cleaning and saw the little ball you spoke of behind a drawer.... so I had to have a look at it, must have put it back out of skew... Really glad you mentioned it as now I can fix and also know what the ball is all about 🙂
Thank you!!

 

[Irish Mist]

Levitation
Thanks for your reply, Howard nailed it. but will also make sure no wires are affecting it...I always like finding out these little things as for sure they will crop up again with me or someone else..
Cheers

 

[Irish Mist]

Howard
Thanks again I was at the boat and was able to turn the ball and realine the autopilot with the GPS As I turned the ball the map moved. This is great for anyone else who finds it out of line check the ball.. Also I noticed the clap hiding it was allowing me to turn it so once where I wanted it I tightened the clamp
Cheers

 

[ReadTheManual]

I suspect electrical interference (RFI) is being generated by the autopilot - probably travelling on the power cables and getting into the MFD... Work on re-routing the power wires and control wires away from any wiring to/from the GPS - and vice versa.. Also route the GPS antenna coaxial cable as far from power wiring as possible..
My autopilot puts a signal on Channel 16 on my radio which forces me to change the channel or shut it off... Have not dug into that one yet bu t it is on my punch list...

You can't be serious... This is a joke--right-? "RFI"... Tsk-tsk. :shock:
Have you even read the manual...?

Additionally, turning the compass ball is not the solution. Swinging the compass and setting north is the solution. Verify no ferrous objects are stored near the CCU (ever) and do a proper calibration as per the manual instructs. Also, your COG and HDG will NEVER match. They are indicating two different things. If after properly calibrating the CCU, the deviation is measurably different in all 4 quadrants, relocate your CCU, and recalibrate. Verify potential points of relocation are viable with a hand-held compass. Good luck. If you have questions, I recommend calling product support, they have been trained... professionally.

RTM: out.

 

[Irish Mist]

Good advise.. I just turned the ball all perfect now
Thanks

 

[Levitation]

Jeez, ball? I don't have no stinkin ball... I do have an electric compass mounted in the forepeak that controls the autopilot... There is no physical alignment for this, just the circling procedure to calibrate it... But a ball? - I'm at a loss... Maybe in my sock drawer? :mrgreen:

Now as far as a VHF radio bothering the GPS - ya boy... If you need a demo I will bring out the old radio from my airplane, set it on the dash in your boat, turn it on to 122.80 and I guarantee your GPS won't even know which planet your boat is on... There were about 6 frequencies that the IF oscillators would magically mix with the VFO oscillator and put out an RFI signal smack dab in the middle of the GPS band...

 

[cgregg2]

I recently purchased a Ranger 25SC-2011. Tug came with empty water tank, filled and turned on pressure pump-I can hear it humming, but no water, checked valve turn offs I could find, all open and still no water. Ideas?

 

[GulfSailor]

I recently purchased a Ranger 25SC-2011. Tug came with empty water tank, filled and turned on pressure pump-I can hear it humming, but no water, checked valve turn offs I could find, all open and still no water. Ideas?

When that same thing happened to us after we filled the tank for the first time and switched on the pump, it turned out that a hose had become detached from the heater and we pumped several gallons of water into the 'cave' before we traced the problem.

If the pump runs, the level in the tank goes down, and there's no pressure at the faucets, you probably have a similar problem.

It could also be a bad pump or a blocked pipe. if so, count yourself lucky as there'll be no mess to clean up and dry out.

For future reference, you should start a new thread for something like this, rather than add it to an existing thread on a different subject; otherwise it'll only be seen by people looking at this 'Autopolot/GPS thread'.