Yam Fuel Mgmt gauge with Raymarine C120W

[max366]

Tried to connect the NMEA output from my C120W to the Yamaha FM gauge instead of using the speedo input. 265 Express 2004 vintage, F225s. Here's what I did:
1. cut the cable from the speedo to the FMG and opened it to get the white wire free
2. checked the + NMEA output from C120 and it varied from 5.67V-0V- jumped around as it is supposed to
3. Connected the +NMEA wire to the white wire on the FMG cable.
4. Checked continuity from the new connection to the pin on the connector- 0 resistance so it was a good connection.
5. Changed the dip switch settings on #6 from its original position which was set for the speedo input. Interestingly, the dip switches are labeled 1-6 but the on-off position appears to be upside down based on the correct position for the lph or gph settings. Not sure what do with #5, so I tried on and off with no change.
6. Checked the C120 output using its diagnostics- both ports 1 & 2 were definitely transmitting data.
Tried this out with the boat going 6 mph- no mpg reading. Changed dip switch position, no difference.
Tried the second NMEA + output port instead of port #1. No difference.
Tried connecting the NMEA - wire to the black on the FMG cable. No difference.
Has anyone connected a C120W with the FMG and if so, how did you do it?

 

[Boat Hound]

I have not done this, but it is on my list. Sounds like you have it right on the money...I would wonder if the fuel flow is not enough to give a reading at 6kts - jump on plane and see what happens. Also use google - there are a number of articles on this.

 

[Salinity Now]

Max, small world, just did the same thing. Did you reconnect the cable back to the Speedo Guage? (the connector has 3 wires, white, red, black) I had to plug it in with the white wire taped off to get mine to work, but its fine as of this weekend.

 

[max366]

Thanks for the repsonses. I wondered about the speed- I'll crank it up tomorrow.
Salinity- do you mean you left the black and red wires still connected to the speedo? I did not try that.
Heard from Raymarine and they indicated the black wire needs to be connected to the NMEA - output, which I have hooked up and will try tomorrow. The other piece of info is that dip switch #5 has to be opposite #6- the Yamaha diagrams are silent on this issue.
More info tomorrow.

 

[Salinity Now]

Yes, I plugged the electrical fitting that was attached to the speedo back to where it was originally (on mine there was only 3 wires, black, white, red) the way I spliced it was by peeling off a large section of insulation in the middle of the cable, cut the white wire, taped the end going to the speedo off, then spliced my NEMA output wire (coming from my Garmin) into the white wire going back into Fuel Management guage, I did not do any grounding, just NEMA out (+) to white wire on FM gauge. I did change the dips on the FM gauge, cant remember exact ones, I just followed the instructions on the Yamaha card, I do remember they werent labeled well, took a gamble and I guess it worked.

Another thing I noticed today, for some reason the economy feature wouldnt work if I turned on the motors first and THEN the GPS, when I did it like that (motor on first) the economy meter showed 0.0 while underway, I cut off the motor (with GPS staying on) cut motor back on and it worked like a charm, this is only the 2nd time Ive run the boat with the new set up, and ive noticed that both times, kinda strange, just a new quirk I'l have to remember about the boat.

 

[max366]

My connections did not work. Ran the boat through the RPM range- no readout. I'll try Salinity's hook up with the red & black wires.

Salinity- do you have a recent Raymarine C type unit?

 

[Salinity Now]

No, just installed a new Garmin 4210, changed the speed input over during the install, Ive been talking with Andy (SIM) on THT about it too, he really helped clear up some confusion and get it to work for me.

BTW, the wire is really small, I used a butt splice and added an extension piece of wire to make it easier to work it, just to cover my butt, I used male/female connectors on the end fittings, that way if i absolutely couldnt get it to work, I could just easily connect it back to the way it was via the connectors (plus modify the DIPs)

check out my link on THT http://www.thehulltruth.com/shipyard-is ... speed.html it has a few extra tips from Andy (he's been a big help with me getting these engines back up to par)

 

[max366]

Finally got it to work. For future reference for others trying to connect a Raymarine unit, here's what to do
1. split open the cable running from the speedo to the FMG but don't disconnect it from the speedo.
2. cut the red wire in two, leave the black alone, cut the white wire and strip the end connected to the FMG
3. connect the NMEA +output to the white wire.
4. fix the dip switches and you're done.

Radio Shack has very small butt connectors used for telephone wire which made the job easier.

Thanks to Salinity because he suggested leaving the wiring from the speedo attached. Turns out the Raymarine unit doesn't need the red wire connected (I tried it and it went beserk).