Fuel Gauge JSO 42DS

[leehadjiosif]

My fuel gauge always shows 3/4-Full no matter how low the fuel is. Would be great if it were true. Anyone else has this experience and any suggestions on how to fix it? I would replace the gauge if I were sure that it would solve the problem and if I had the part number. Could it be a malfunction with the Jeanneau display panel? My tank is plastic 127 Lt. Thanks
Lee

[John]

Hi Lee ,

The gauge on our 42i should be the same it was not reading as it used to sometime ago , I removed the sender and wiped it clean then worked again , it can be tested by moving it when its out of the tank .

John

[deepblue]

Hi Lee,

Had the same problem in 42i. Sender was at fault. Replaced it with the same unit from VDO.80 Euro or so.
15 min. job. Have since also mounted a VDO fuelgage next to enginepanel near the helm. Prefer not to be to dependent on the
French made mainpanel.

[calipir8]

I did the same as deepblue, installed a fuel gauge at the helm, as well as a temp gauge.  

[Mistroma]

It was always dodgy on our 2009 42DS and didn't match the fuel added. The tank shape meant it was worse at lower levels. I put an upward curve in the float arm and this improved low level readings at expense of higher levels. It also tends to stick and jump up/down. Readings also change randomly if any poor connections so I dismantled connectors, tightened cleaned and use Contra-Lube 770. Still not great but seems workable at present with my Arduino based replacement.

e.g. For my tank....
>138 Ohms is max. (sometimes up to 140 Ohms) is in range 95 or 100 to 130 litres
Below 138 Ohms it's calibrated to b within 0-5 litres of actual fuel level
Around 58 Ohms the level is between 10-20 litres.

You can't calibrate the standard Scheiber display. All you can do is thry to get the sender working reliably and then make a lookup table of display value vs. actual fuel level.

[ohana]

Have exactly the same problem. My plan is to replace the fuel level sensor as it seems to be sticking. Spoke with WEMA UK, gave them the part number on the fuel tank sender. Interestingly they have advised this is a "special" for Jeanneau, calibrated to suit the odd tank shape. 

However, I plan to buy a direct replacement linear sender, with more resolution, and a new gauge which can be calibrated on initial tank fill to correspond with the amount of fuel added on first fill. Am considering a CruzPro FU 60 Digital Fuel Gauge. 

[Mistroma]

Oct 22, 2018 21:48:55 GMT ohana said:

Have exactly the same problem. My plan is to replace the fuel level sensor as it seems to be sticking. Spoke with WEMA UK, gave them the part number on the fuel tank sender. Interestingly they have advised this is a "special" for Jeanneau, calibrated to suit the odd tank shape. 

However, I plan to buy a direct replacement linear sender, with more resolution, and a new gauge which can be calibrated on initial tank fill to correspond with the amount of fuel added on first fill. Am considering a CruzPro FU 60 Digital Fuel Gauge. 

Surprised to hear the sensor is a "special". I assume that they really just mean standard one at 3-4 times normal price.

The 42DS water tank gauges could easily be made to read correctly in 25% increments. Still only an indication though as 75% would actually mean between 75% and 51%.

The Scheiber unit just displays 25% for each sensor (i.e. s/s screw) covered in water. All Jeanneau need to do is work out where to fix the screws and use a template when inserting them. However, it seems more likely that they are fitted in "roughly the right place" by eye.

I doubt they'd spend much effort on fuel level Jeanneau don't seem to give any consideration to water tank level accuracy. It is more important but I really doubt they went to the trouble of having a special sensor made just for the 42DS. Putting a slight curve in the float arm has quite a big effect on linearity. I managed to improve our readings by curving the float arm, all guesswork though. Much easier to use a different sensor and calibrate it yourself.

[ohana]

The Wema unit fitted in my Jeanneau is a special in that it is a special calibration of a standard unit. This was confirmed to me by the wema uk guys who could not initially trace the serial number I gave them, but eventually came back to confirm that it was a special calibrated version. Would make sense, given jeanneau will fit hundreds of these tanks. 

The standard wema linear calibrated replacement offers 10 graduated outputs, but there is a version with double the resolution which I plan to fit. This with a new programmable meter from cruzpro FU 60s

[leehadjiosif]

Oct 12, 2018 22:00:07 GMT leehadjiosif said:

My fuel gauge always shows 3/4-Full no matter how low the fuel is. Would be great if it were true. Anyone else has this experience and any suggestions on how to fix it? I would replace the gauge if I were sure that it would solve the problem and if I had the part number. Could it be a malfunction with the Jeanneau display panel? My tank is plastic 127 Lt. Thanks
Lee

Today I removed the fuel gauge to investigate and clean it. Nothing much to clean really. Anyway, I showed full when the float was either in the full up or full down position, and it showed half (correctly) when the float was at 90 degrees (outside the tank). Very confusing since I don't know if it's the sender or the gauge in the Jeanneau panel. Here are some pics. If anyone had the same sending unit and replaced it successfully I would like to know the details. Thanks.




www.23hq.com/LeeH/photo/48055048/original


www.23hq.com/LeeH/photo/48055524/original

[ohana]

This is the WEMA sender unit removed from my tank earlier today. I am going to test it, but still plan to change to a higher resolution version as mentioned before


www.23hq.com/ohana/photo/48059771/original

[leehadjiosif]

Oct 12, 2018 22:00:07 GMT leehadjiosif said:

My fuel gauge always shows 3/4-Full no matter how low the fuel is. Would be great if it were true. Anyone else has this experience and any suggestions on how to fix it? I would replace the gauge if I were sure that it would solve the problem and if I had the part number. Could it be a malfunction with the Jeanneau display panel? My tank is plastic 127 Lt. Thanks
Lee

Has anyone replaced the old fuel sending unit on a JSO 42 with a 127 LT capacity tank and successfully used the existing wires to the Jeanneau panel gauge? I don't want to add a separate gauge. If yes, what model and length? Thanks. Lee

[ohana]

I have now ordered a new WEMA sender, 300mm high resolution to replace the existing. Easy enough, straight swap. I have also ordered a CruzPro FU60, which I will need to fit somewhere near the chart table. This gauge is programmable, so I will empty the tank and then refill in 10 litre amounts to calibrate the new gauge (tank is 200 litre capacity)

Will post updates for those interested.

[leehadjiosif]

Will the new sender communicate with the existing digital gauge on the Jeanneau panel or rely entirely on the new gauge at the helm?

[MalcolmP]

Nov 9, 2018 14:33:51 GMT ohana said:

I have now ordered a new WEMA sender, 300mm high resolution to replace the existing. Easy enough, straight swap. I have also ordered a CruzPro FU60, which I will need to fit somewhere near the chart table. This gauge is programmable, so I will empty the tank and then refill in 10 litre amounts to calibrate the new gauge (tank is 200 litre capacity)

Will post updates for those interested.

Would make good new hints and tips article if you could supply brief notes and photos 😊

[ohana]

Nov 9, 2018 16:13:00 GMT leehadjiosif said:

Will the new sender communicate with the existing digital gauge on the Jeanneau panel or rely entirely on the new gauge at the helm?

Needs a new gauge. The one on the switchboard is very basic, i will still use this for the 2 water tanks but thats it. I have fitted a Mastervolt battery monitor system (monitoring current and voltages so gives me overall % capacity for batteries at all times).

[Mistroma]

Interesting, it looks as if WEMA use a sealed tube containing an array of reed switches triggered by an external magnet on an annular float. I can see how that would be much better than the normal partially immersed rheostats operating with a float arm. It should be much more robust with very reproducible readings. Output will depend on which reed switch is activated (i.e. One nearest the magnet in the float) and set to be in range for either European or US standard type of sender).

I'll need to check their template vs. my existing sender and find out max. tank depth where existing sender is fitted. Unfortunately, that might need to wait until next year. The position of te existing sender might be aslight problem. It isn't directly above the deepest part of the tank because the arm sticks out to one side and that sits over the deepest part. I wouldn't want to drill another hole because the existing sender sits in a reinforced part of the tank to give purchase for the retaining screws.

I suspect that won't matter too much as the sender will still be accurate from the lowest point upwards. My present sender is pretty accurate from 10 litres upwards but stops changing around 100 litres. It also sometimes jumps from usual max. to a much higher reading in Ohms when full. I'd be happy if it was accurate from full down to 20 litres and that seem likely. I still log engine hours and use that to get a pretty good indication of when to fill but it would be nice the have a reliable gauge.

Finally happy with the water tanks though, the Arduino based system is spot on, even though it only reports in steps and Jeanneau were pretty random in where they fitted the level screws.

[ohana]

Whats the Arduino based system you refer to? Not heard of this before...

[Mistroma]

I've mentioned it here before and am trying to find time to write it up. My Schieber unit failed last year and I built a replacement system.

I/O board was easy enough and designed to operate at 100V max. so much lower chance of problems due to a spike in 12V system. Accuracy is fine for all sensors but fuel sensor itself tends to stick.

Display was a problem as I couldn't find a transflective unit with close match in size. I settled on a parallel unit which used most of the pins on an Arduino. I was going to serialise the display connections by building another board but decided it was simpler to use a second Arduino to handle I/O (sensors and buttons). They communicate via serial and it works well.

However, I haven't implemented a menu system yet and wanted to do that before posting details.

I posted a picture in this thread. jeanneau.proboards.com/thread/6741/scheiber-panel

Display was still 2mm out of alignment as I hadn't actually bolted it into place.

[ohana]

Thanks, this is an impressive approach! Not sure I would have the capabilities to do what you did, hence cheating and buying the CruzPro. Hopefully it will work OK