NMEA Fuel Sender Problem

M

mathias999us

New member
Hi Folks,

I've got a new to me 2009 Venture 26. It has two Suzuki SMIS guages at the helm, and apparently the surveyor missed the fact that they are only registering the port tank sender. The starboard tank sender does not appear in the bus device list. I started digging into the wiring around the fuel tanks in the rear, and found that I have two of these devices:

https://www.brownspoint.com/store/pc/pdf/SMIS_Fluid_Level_Manual.pdf

It looks like this is also a direct / rebadged Lowrance EP-65R unit.

One is connected to each tank, and the other ends are connected to the terminal end of the nmea network with T's and finally the terminating resistor.

I've swapped around the connections, and sure enough, the port tank sender reports itself on the network bus device list no matter where I plug it in, and the starboard sender is absent from the list.

I'm new to NMEA stuff. Is there something else I should check, or should I just be looking into ordering another one of these units? Looks like they are about $90.

Is it common for a component like this to go bad?

Thanks,
Mathias
 
Did you hook up the port sender's terminals to the Stb tank? It is possible that you have a bad sender unit, corrosion, or that it is not properly hooked up. I believe that you would have to have some current flow to register the "sensor" NMEA 2000 EP 65. You can check the resistance of the pot in the sender unit to see if the sender is bad or good. Empty it should read about 240 Ohms, Half way about 105 Ohms, and full about 33.5 Ohms.

The sensor unit is solid state, and should be OK--Sorry, I don't know how to test it. But if connections are bad.. Also if any of the original connectors are left on the sender unit, the sensor may not work.

I assume that you went thru the entire re-configure procedure? Are you sure it is set for two tanks?

Yes, the Lowrance and Suzuki parts are the same.
 
Thanks Bob - these are some great suggestions.

I have not messed around with the sender-side of the units yet, only the network ends. I'll get out there with the multimeter tomorrow and see if I can measure direct at the sender. I seriously hope the sender is okay - looks like a major pain to pull the tanks. They are hard enough to access to begin with.

The resistance measurement is a good idea. Another good test would be to see if the working unit still presents itself on the network if I disconnect it from the sender. None of the network connections looked corroded or weathered, and the solid state parts seem to be in good shape visually.

I have not gone through the entire re-configure procedure. I can confirm that when I disconnect the good sensor from the network it disappears from the bus device list, and when I reconnect it, it appears again. I assume the other should behave that way also. I can also confirm that it is set for two tanks in the setup. Both tanks are full, and it reads vessel fuel at exactly 50%.

Will circle back when I have more data.
 
There should not be any reason to remove the tank… That involves a bunch of Fein saw type of work! However, none of this is easy!

Just wonder about the 50% fuel--I would think that each tank reads separately? I didn't go with the senders, just the flow meters.

Where are you getting the fuel flow/ From two EP 60R or from the engine computer?

Disconnecting the port from the sender is a very good idea, and I suspect it will disappear.
 
I think the tanks in the Venture 26 can be removed without any fiberglass work? There are just panels in front of them that unscrew, and the unbolt from the deck and slide out. But, there are hoses and wires attached, wires and other hoses to watch out for, etc. Getting them back in would be even worse. I'm just not certain that there is enough vertical clearance in there to remove a sender if one turns out to be bad.

Yah, there is a "combined" vessel fuel page that shows 50%. Then there is a Port fuel tank page that shows 100%, 50 gallons. The setup is configured for 2 50gal tanks righ now, and I guess it deals with the absence of a second tank sensor by treating it as empty. I believe the fuel flow is only from the engine computer. If this turns out to be a pain to fix, I suppose I could rely on that as a stop-gap. I'd like to have it all working though.
 
Thanks I did not realize that the tanks came out that easily--or so it would seem.

Yes, I just used the calculation on the EP 60's for fuel, Worked good enough for me. But if you have the system, you might as well use it, and it is a bit handier, and probably a good safety back up feature.
 
Ok, I dug into the area around the tanks. I disconnected the port (working) EP65R from the tank sender, and it did indeed still present itself on the network, with just an empty tank reading (the tank is completely full). Then, disconnected the starboard EP65R from the tank sender and measured the resistance from the sender. 135 ohms. I've had the boat out twice since the tank was filled, and this is the tank I've been using. One of the trips was a little over 50 miles planing, the other was 15-20 miles of mixed speeds, and some time idling and breaking in the kicker. Over halfway full per your ohm figures Bob, so this is about exactly what I'd expect. I'm really glad, because there is literally ~3 inches of clearance above the tanks. Replacing a tank sender would require removing the tank. I had all I could do to get to the location where the wires attach to the sender, with my shoulder buried in between the gas tanks and my forearm crammed between the tank and the underside of the motor well. I came out of it with some nice scrapes and cuts on my arm.

But, I was able to get the alleged offending part removed:
20150524_105907.jpg

I was able to put everything back together including the wire connections at the tank, so installing the new EP65R will be a lot easier than it was to figure out how to remove the old one. I'm placing and order for a new unit, and will post final results after I finish the job.

Thanks for your help.
 
Great job.

Did you attach some leads to the sender, so you only have to crimp two wires to install the new sensor?

Sure sounds like it is the sensor--but one never know 100% until it is replaced.
 
Thanks Bob - yeah, there were already leads in place from the tank sender, with crimp connectors buried up under the starboard gunwale in the wiring harness, inside some wire loom. I had to remove the leads and trace the lines to learn this, but now I know where the connection points are, so installing the new unit will be less than a 20 minute job to have everything back in place. Just a little routing of the wires, two wires to crimp, and some new zip ties.

Also I will add, I played around with the supposed defective unit after I got it out, plugging it into the different ports on the NMEA bus, and I tried it with the sender leads disconnected, and also with them shorted together, and I could not get it to show up in the bus device list with anything I tried. It's almost certainly defective. I don't see anything at all wrong with it visually. All the wiring looks to be in good condition, and no sign of cracks, water intrusion, etc. on the inline units.
 
mathias999us":2v2leoci said:
Hi Folks,

I've got a new to me 2009 Venture 26. It has two Suzuki SMIS guages at the helm, and apparently the surveyor missed the fact that they are only registering the port tank sender. The starboard tank sender does not appear in the bus device list. I started digging into the wiring around the fuel tanks in the rear, and found that I have two of these devices:

https://www.brownspoint.com/store/pc/pdf/SMIS_Fluid_Level_Manual.pdf

It looks like this is also a direct / rebadged Lowrance EP-65R unit.

One is connected to each tank, and the other ends are connected to the terminal end of the nmea network with T's and finally the terminating resistor.

I've swapped around the connections, and sure enough, the port tank sender reports itself on the network bus device list no matter where I plug it in, and the starboard sender is absent from the list.

I'm new to NMEA stuff. Is there something else I should check, or should I just be looking into ordering another one of these units? Looks like they are about $90.

Is it common for a component like this to go bad?

Thanks,

Mathias
Click to expand...




Go see your favorite Suzuki Dealer they are rumored to have a fix for their Lorance / Suzuki $400.00 gage.
I ended up putting the old fuel gage back in.
:wink:
 
Doh! Well, I've already ordered the other sensor, so I guess we'll see if that was the issue. Do you have any more info on this rumored fix? I can't seem to find anything about it searching the net.

Mathias
 
They are analog sender units on the tanks, and then the leads of the ep65r unit, pictured above, connect to the sender terminals and convert the reading the nmea 2000 network data. I've found the manual for the units....

Tsturm seems to indicate maybe there is a firmware update or something similar for the display units. It sure seems like a bad ep65r unit to me though.
 
Those are really neat though Brent. I saw some like that that used soundings to measure fluid volume, but could be used on freshwater and blackwater tanks. That would be nice to be able to get those readings hooked up to the NMEA 2000 network in the boat.
 
The new EP65R showed up today, and I hooked it up and sure enough - I got an "unconfigured fuel level sensor" to show up in the bus device list in addition to the port fuel sensor. I configured it as fuel, starboard, 50 gallons, and now everything's working! Woohoo! Thanks for all of your help.

Mathias
 
Thanks Bob - yeah, the surveyor missed a few things here and there on this boat. That's okay I guess - it's a boat, so I expect that it will just be ongoing throughout the time that I own it. Another item checked off the list (for now).

Brent - your guess is as good as mine. It looked perfectly fine, but then again these machines live in a harsh environment, and are full of delicate hardware protected by thin layers of plastic.
 
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