Go Back  The Hull Truth - Boating and Fishing Forum > BOATING FORUMS > Marine Electronics Forum
Reload this Page >

Yamaha Fuel Management Gauge show dash on mpg

Notices
Marine Electronics Forum

Yamaha Fuel Management Gauge show dash on mpg

Old 08-28-2017, 02:24 PM
  #1  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jul 2008
Location: Palm City, Fl
Posts: 290
Received 34 Likes on 22 Posts
Default Yamaha Fuel Management Gauge show dash on mpg

I took the boat out after replacing the steering RAM and installing the autopilot and the Fuel Management Gauge shows only a dash (-), it does not measure anything at any speed.
I have to assume that something got disconnected with all the hose routing and bleeding.
I didn't see any wire disconnected coming out of the gauge. before I go and start plugging and unplugging wires, I figure I ask here to see if anyone can point me in the right direction.
the other gauges work fine, speed, rpm, gas level, trim, etc etc they all work, even the mode and set on this gauge works, I can move between selections with no problem.
these are 2005 classic round gauges connected to twin 225s and the mpg was working a couple of weeks ago.
the fuel sensors were replaced in April, I doubt they went bad this quickly but it's a possibility.

Any help is appreciated,

Sam
Old 08-29-2017, 02:58 AM
  #2  
Member
 
Join Date: Sep 2016
Posts: 81
Likes: 0
Received 4 Likes on 3 Posts
Default

Take a look near your fuel/water separator. Somewhere you should have a fuel flow sensor. Maybe that got unplugged?
Attached Images  
Old 08-29-2017, 06:41 AM
  #3  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jul 2008
Location: Palm City, Fl
Posts: 290
Received 34 Likes on 22 Posts
Default

I'll check but I doubt that both got unplugged at the same time. those were replaced back in April
Old 08-30-2017, 11:49 AM
  #4  
Admirals Club Admiral's Club Member
 
Join Date: Jul 2007
Location: somewhere in FL
Posts: 2,024
Received 139 Likes on 85 Posts
Default

Do you show "-" for fuel flow on each motor or for fuel economy. If you have fuel flow, but not economy, you may have accidentally pulled the pitot line or it could be plugged (if you are getting this signal from the pitot and NOT a gps). If you do not have fuel flow, check the connections to make sure they are clean. I've bypassed the connector on one of mine due to corrosion where the wire goes into the connector.
Old 08-30-2017, 12:34 PM
  #5  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jul 2008
Location: Palm City, Fl
Posts: 290
Received 34 Likes on 22 Posts
Default

shows "-" for the top line, I can't remember if it's gph or mpg, the bottom line stays at the last number, i forget what it says but let's say 17.1 or so even when coming back from sync.
the speed and RPM are correct as well as the tilt and fuel level.
is the pilot line the one for the speed?

thanks,

Sam
Old 08-30-2017, 08:39 PM
  #6  
Admirals Club Admiral's Club Member
 
Join Date: Jul 2007
Location: somewhere in FL
Posts: 2,024
Received 139 Likes on 85 Posts
Default

Can you post a picture?


The pitot is for speed, unless you are getting it from the gps.


Need to know if its gph or mpg on the fuel management gauge (FMG).


Does the FMG show a "P S" in the left side of the gauge? That will tell you if the gauge is reading the signal from both fuel flow sensors. If one is missing it won't show up on the gauge display (P or S)


rpm and speed are on separate gauges
Old 08-31-2017, 06:16 AM
  #7  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jul 2008
Location: Palm City, Fl
Posts: 290
Received 34 Likes on 22 Posts
Default

I will go to the boat today and take pictures.
I have a feeling it's a disconnected wire but I don't know where.

thanks!
Old 08-31-2017, 04:19 PM
  #8  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jul 2008
Location: Palm City, Fl
Posts: 290
Received 34 Likes on 22 Posts
Default

ok, I wiggled the wires and it shows 0.0 on the gph and 71.0 on the gallons.
1st pic is the gauge
2nd pic all the wires coming out of the FMG
3rd back of the gauge
4th fuel flow sensors
5th green wire to starboard motor gauge
Attached Images      
Old 08-31-2017, 04:25 PM
  #9  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jul 2008
Location: Palm City, Fl
Posts: 290
Received 34 Likes on 22 Posts
Default

Green white to port motor gauge.

I don't know why it doesn't show P S for both motors.

I think I am getting there, if not fixed but I won't know until I take it to the water and test but now the tilt/trim on that motor doesn't come down and I need to replace the seals... Break Out Another Thousand, right?
Attached Images  
Old 08-31-2017, 05:12 PM
  #10  
Admirals Club Admiral's Club Member
 
Join Date: Jul 2007
Location: somewhere in FL
Posts: 2,024
Received 139 Likes on 85 Posts
Default

Was the motor running when you powered up the gauge? It won't register until there is flow going through the sensors.


If you had to wiggle wires to get things to work, you may want to check all your connections. The connections at the sensor(s) is usually in a more corrosive location. PM me your email and I will send you the gauge manual.
Old 08-31-2017, 05:29 PM
  #11  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jul 2008
Location: Palm City, Fl
Posts: 290
Received 34 Likes on 22 Posts
Default

the keys were turned enough to power the gauges but the motors were not running. the boat is on the trailer.

thanks!
Old 09-02-2017, 05:18 AM
  #12  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jul 2008
Location: Palm City, Fl
Posts: 290
Received 34 Likes on 22 Posts
Default

well, that was a biatch to remove the cap on one of the cylinders on the tilt/trim motor. had to chisel it out. luckily the parts place was a block away and they had a replacement cap.
thanks for all your help, we'll see if it's working this weekend.
Old 09-06-2017, 06:38 AM
  #13  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jul 2008
Location: Palm City, Fl
Posts: 290
Received 34 Likes on 22 Posts
Default

Well, took the boat out on Sunday and same thing, a dash on the gph and the mpg, the gallons are not moving, reset to zero and stayed there for the 8 hours the motors were on. tried wiggling the connectors, plugging and unplugging, turn motors off and on, nothing.

I am out of ideas other than replacing the fuel sensor in the back.

any other ideas?

thanks,

Sam
Old 05-01-2018, 01:55 PM
  #14  
Admirals Club Admiral's Club Member
 
Join Date: Aug 2003
Location: League City, TX
Posts: 1,163
Received 204 Likes on 125 Posts
Default

Did you ever figure this out?
Old 05-01-2018, 02:18 PM
  #15  
Admirals Club Admiral's Club Member
Thread Starter
 
Join Date: Jul 2008
Location: Palm City, Fl
Posts: 290
Received 34 Likes on 22 Posts
Default

Yep, one of the two channels of the gauge was bad, replaced the gauge and the wiring (just in case) and it's working now.

Thanks,

Sam

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information -

Copyright © 2021 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.