This Seneca fuel gauge is driving me crazy

Rick-in-Houston · 10-11-2016, 02:04 PM

I know there has been discussions on this forum about the Seneca fuel gauge not reading accurately. My is so far off that it is driving me crazy and I need to get it repaired. I found a service bulletin (54-281) about the fuel level sender guard fix. Has anyone had this issue repaired or any other thing done that has solved your fuel gauge problem?

Old skipper · 10-11-2016, 02:53 PM

What is the story on the fuel level sender guard? Is that a Freightliner service bulletin?
Is your gauge irratic or just not accurate? Mine appears to be fairly reliable.

memphis02 · 10-12-2016, 06:09 AM

Mine was off by about half the tank. Needle would be buried on E with 35-40 gal left.

Get a scanguage-d, worry no longer.

AaronM · 10-12-2016, 08:12 AM

I know on mine I just had to change the way I interpreted the gauge. The 'E' on my Seneca means start looking for a convenient place to get fuel. The 'E' on my F250 means you had better be pulling into a fuel station or you're in trouble.

My Seneca gauge is consistent and that is all that really matters to me. Now, if it ran out of fuel while the gauge was at random positions... that would be a problem.

tom463219 · 10-12-2016, 04:03 PM

Just my 2 cents, but I drove over the road for almost 40 years. Everything from Macks to Volvos to Freightliners. Never did drive anything that had a totally accurate fuel gauge. Best way is to know your approximate mpg, the gallons of fuel on board and keep track of the miles you drove.

RyRoRyan · 10-12-2016, 06:51 PM

So is the scan d reading the fuel sending units correctly and the gauge itself is not? So let me ask this...if the gauge is reading E but you still have 25 gallons left (above 1/4 tank in real life) does the generator still run? Just wondering if the faulty gauge will cause the generator to not run. If the sending units are fine and a scan d can read it fine, I would hope the generator would read that correctly and run to real life 1/4 tank. Anyone have any first hand knowledge with this?

Paintinfool3 · 10-12-2016, 06:57 PM

I was talking to a guy yesterday that owned a 2014 and he said his was reading empty when he was a little over a 1/4 tank left. Now if you consider that is where the Gen set should stop running maybe that's what they figure it on. I know my genset would shut down on my old motorhome at 1/4.

AaronM · 10-13-2016, 06:29 AM

The generator fuel pickup is located 1/4 up from the bottom of the fuel tank. It does not use the gauge. Once the fuel level drops below the pickup it dies. My generator runs fine with the gauge on E.

The scangauge does not read the fuel level at all. It just tells you total gallons used. Just reset it after a fill up and it will tell you, with pretty good accuracy, how much fuel the injectors have sprayed into the engine. It will not record generator fuel use but that is pretty minimal.

RyRoRyan · 10-13-2016, 09:41 AM

What tank does it pickup from? I dont have one yet...but very will might in the next few weeks. If I recall correctly each tank is not the same size (I think due to the DEF tank on one side). I am hoping that it is attached to the larger tank so it takes longer to get to 1/4 on that side?

Les7h · 10-16-2016, 08:13 PM

I love the ScanGauge D - it reads the info from the computer & is very accurate

AaronM · 10-17-2016, 07:38 AM

Quote:

What tank does it pickup from?

The driver's but there is a crossover hose that connects the bottom of the two tanks so it really should not matter.

Old skipper · 10-17-2016, 08:58 AM

It takes a fairly long time to equalize. I must have the only somewhat accurate gauge if I fill at 1/4 tank I take 38 gallons on the passenger side and 12 on the drivers and those numbers are repeatable.

RyRoRyan · 10-17-2016, 09:38 AM

If this were true would not the tanks cross fill? I was under the impression that the tanks were independent and would not cross fill to each other. Or is it that it is coupled but the hose a much smaller diameter than a filler hose so it would not have enough flow to actually cross fill the tank from the other side faster than an actual pump?

Robbbyr · 10-17-2016, 09:52 AM

In case anyone is interested in learning more about how our Seneca's fuel equalization system works I have attached a document that has some information on the system. While a transfer hose connecting the bottom of our fuel tanks would be more simple and would possibly allow filling from just one side, they are vulnerable to damage and then dumping the entire contents of both tanks onto the road. Sometimes debris in the road gets kicked up and damages the transfer line. Our units could be vulnerable to that scenario if they had a lower transfer line.

In my "prior-to-retirement" life as a career firefighter we had numerous instances where a semi-tractor damaged the transfer line and dumped hundreds of gallons of diesel that we then had to contain. Very costly to clean up!

AaronM · 10-17-2016, 10:10 AM

Quote:

Our units could be vulnerable to that scenario if they had a lower transfer line.

Does your Seneca not have a hose at the bottom of each tank connecting the two tanks? Mine does. I also have another Freightliner M2 truck and it does not have that hose. Maybe something that Jayco adds? Maybe for the generator usage when the engine is not running to equalize the tank level?

Old skipper · 10-17-2016, 10:28 AM

Here I thought the fuel return line only went to the passenger side on our trucks. Good information especially as we travel roads that have no truck stops or travel centers. I have been in the habit to find a station I could fill the passenger side then drive to the next station I could get the drivers side especially when towing the one ton dually.

Robbbyr · 10-17-2016, 10:49 AM

Quote:

Originally Posted by AaronM

Does your Seneca not have a hose at the bottom of each tank connecting the two tanks? Mine does. I also have another Freightliner M2 truck and it does not have that hose. Maybe something that Jayco adds? Maybe for the generator usage when the engine is not running to equalize the tank level?

Mine does not. I have attached a picture from underneath that shows my setup. The engine supply and return lines come off the side of the two tanks and curve up and over the transmission where they connect to the equalization system components. Nothing connecting the bottom of the two tanks directly. My chassis was manufactured in late-2013, I wonder if Jayco or Freightliner changed something?

The crossover lines I saw on semis were a hose of at least 1" diameter, sometimes bigger. Does yours have something like that?

RogerSwann · 10-17-2016, 10:53 AM

My 2013 chassis (2014 37fs) will equalize over time if I just fill one tank. Filling the left tank will indicate full on the gauge, filling the right one has little effect on the fuel gauge.

AaronM · 10-17-2016, 11:34 AM

Quote:

The crossover lines I saw on semis were a hose of at least 1" diameter, sometimes bigger. Does yours have something like that?

It does, yes. Has a valve on each end also. I will get a picture tonight.

Robbbyr · 10-17-2016, 11:38 AM

Quote:

Originally Posted by AaronM

It does, yes. Has a valve on each end also. I will get a picture tonight.

Very interesting. Look forward to seeing what it looks like.
Did you purchase your unit new?

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