Something triggered a system reset on our B&G instruments in 2008...Boat Speed and the Wind Speed analog instruments appeared reversed.  We were at anchor with about 10 knots of wind.  The needle on the Boat Speed was at a 9:30 position and the Wind Speed was registering zero.  I realized that a position of 9:30 on the Wind Speed would be about 10 knots.

I found that section 5.3.2 of the Hydra 2000 User Manual details how to “Configure the Analog Indicators.”  This procedure allows you to specify which values are sent to each analog instrument.  I went through the steps in the User’s Manual and configured the Wind and Boat Speed correctly.  If your Amel is like my Amel, the default settings will reverse Boat Speed and Wind Speed and you will have to “Configure the Analog Indicators.” 

I copied and saved this posting by Gary Silver almost 9 years ago regarding connecting to the NMEA out on the B&G FFD:

A couple of warnings are in order. 

1.  Radio frequency interference (RFI) evidently can cause

the NMEA interface to glitch so careful routing of

properly shielded and grounded wire is important. 

2. Use twisted pair shielded high quality wire, avoid running it

right next to the SSB or VHF antenna cables or other

high current 24 vdc power wires, and ground the shield

at only one end of the wire run (I grounded mine at

the Hydra 2000 NMEA display cable). 

First the connections at the Raytheon autopilot computer. You are going to be feeding the NMEA heading information to the B

& G so that the Hydra 2000 can calculate true wind.

You use the "NMEA output" from the Raytheon computer

(this is located in the cupboard above the sink,

between the 220 VAC and 24 VDC circuit breaker panels and

is mounted on the forward side of the cockpit

bulkhead on which the helm wheel is mounted). 

The cover is removed by depressing two tabs on either side of the

cover and sliding it downward. The wires should be

tinned, the shield trimmed off and covered with heat

shrink within about two inches of the terminal strip and

they are inserted by pushing down on the tab and

sliding the wire into the terminal hole. Just look at the

other wires to get the direction of the hole. 

Route the wire towards the port side, then via the access tubes

into the access area behind the analog B & G

instruments via the sliding ceiling access panel in the

kitchen. Use one of the un-used conduits to thread the

wire into the starboard quarter-berth area. 

Then by removing a small piece of trim in the bookshelf area above

the nav station hanging locker you can route the wire

into the nav station area. Leave enough slack to allow

the rack system to be removed easily. 

Attached is the info from the B & G technical support: DO NOT ATTEMPT

TO USE THE NMEA INPUT OUTPUT terminals on the Hydra

processor (i.e. the B & G computer) Instead the NMEA

connections must be made through a NMEA FFD on HYDRA

systems.  

B & G tech support states: The solution will be to

locate your NMEA FFD, and connect the wires from your

Raytheon as follows: 

Raytheon NMEA Output (+) Brown 

NMEA Output (-) Blue 

NMEA FFD NMEA Input (+) Violet 

NMEA Input (-) Black 

The wire shield is grounded by connecting to the other

grounds at the hydra processor. The above wires

are from the cable coming from the Hydra 2000

display. You will find that they are capped. Just pigtail

them together as indicated.