refer fighting autopilot

[stacy]

Friend of mine finally replaced his 20+ yr old alpha autopilot with a Raymarine 6002 smart pilot. On their first trip with this new AP, crossing the Sea of Cortez, every 7 min the AP would do a 25degree couse change to port. When they finally arrived off the coast of Baja they re-initalized the AP and took the boat out again and it did the same thing. They turned off their Adler Barbour 12 volt refer that uses 6 amps when running and this has cured the problem. There was no low voltage problems as they were motoring the whole time. The 2 systems are on different circuit breakers. Any suggestions as to how to have both systems running at the same time would be appreciated. Thanks

[skipmac]

I have read comments about the A-B being electronically very noisy. My guess would be the electrical noise from the refer is being picked up by the AP controller.

I read a post somewhere about the steps someone took to reduce the electrical noise in the refer. Will do a search to see if it pops up.

[Don L]

If the AP and frig are are being powered from the same panel try running the power for the AP directly fused to the battery. Raymarine AP don't like to share power with others!

[senormechanico]

Where is the autopilot's compass? Next to the compressor?

[jeremiason]

A consistant 25 degree corse change may not be related to the AB, but to the power consumption...

I installed a Raymarine Auto pilot on my last boat and the fluxgate compass was mounted near the main battery cables. The Autopilot worked fine when I had fully charged batteries, but when the batteries were low and the alternator was doing its 85 amps... It would throw the Fluxgate compass off...

The problem was solved when the installer move the compass away from the electromagnetic field....

I would check the Fluxgate compass location for any near-by power wires, especially the large main cables.

[stacy]

Thanks for the replies! I have sent all of them on and will post a response when I hear back from my friends.