Autopilot Fix - Need Ideas

[DRS]

So heres the situation. B&G auto pilot is not working. The control unit compass counts down from 360 constantly. I've had the brain and compass out to a local shop they tested ok but sent them to B&G who tested them ok as well. The units were reinstalled and the installer can't get it to work. Powers up but the brain is not seeing the compass or rudder position. Continuity of the wires checks out ok.

Where do we look next? Any ideas are greatly appreciated.

[nonam]

Spray all the plugs and other connections with Caig Deoxit ,or similar product.

[Lancerbye]

Programming error, wrong mode?

[phantomracer]

what fluxgate are you using? having the same problem with my KVH (2 have done this). Having them repaired at the moment.. Not sure what is causing this either.

[barnakiel]

Get a similar fluxgate from another boat and you will know whether it is the fluxgate or the unit.

Measure the fluxgate - it will deliver something if it is OK - B&G will tell you what to expect.

b.

[Lancerbye]

Since you are not getting the information from either the rudder positioning feedback or the fluxgate compass there has to be a common link between the two. The only link I can think of is the voltage to the system. Check the voltage at the control head and also going to these two independant system components at the component. A bad conection will still show continuity but can drop the useable voltage below the required amount at the component.

[donradcliffe]

Originally Posted by Lancerbye

Since you are not getting the information from either the rudder positioning feedback or the fluxgate compass there has to be a common link between the two. The only link I can think of is the voltage to the system. Check the voltage at the control head and also going to these two independant system components at the component. A bad conection will still show continuity but can drop the useable voltage below the required amount at the component.

a big +1 on this advice, especially if things check out at the shop (where there is enough power). OTOH, I have heard of B&G pilot compass failures...I have also seen similar problems when the compass is mounted near a magnet.

[Lancerbye]

Originally Posted by donradcliffe

a big +1 on this advice, especially if things check out at the shop (where there is enough power). OTOH, I have heard of B&G pilot compass failures...I have also seen similar problems when the compass is mounted near a magnet.

Also a big plus on the magnet close to fluxgate compass. The only time I ever had a problem with my system was when my late wife ordered and installed a magnetic mattress pad on our bed. She was a sucker for a good sales pitch. The fluxgate compass is installed at the foot of the bed and was about a foot away from the magnetic pad. This caused a bit of head scratching until I discovered what had happened.

[DRS]

So here's the update. We hired another "expert" who looked at the system and declared the connections were not up to ABYC standards. Re-did the conections and the pilot is working

[donradcliffe]

Thanks for sharing that with us. Yet another case where corroded connections are the root cause--something you can look for before you call in the $expert$.