Tank Indicator Inop--how to test?

[jimlay]

Greetings all;

I have a tank indicator that is wired to all 3 of my fresh water storage tanks as well as the diesel fuel tank. It hasn't worked since I bought the boat and it's time for me to troubleshoot. If you all wouldn't mind, where/how do I check the outputs from the in tank sensors (I have a voltmeter) to make sure that they are working properly? What would be the best way to go about figuring out what pieces/parts need to be replaced, refused or otherwise reset to make the system work for me? I know that the indicator panel is WEMA......don't yet know manufacturer for the sending units.

The boat is a 1997 Hunter 450 Passage.

Thanks

Jimlay

 

[Peggie Hall HeadMistress]

Are the senders inside the tank?

If so, they're also certain to be Wema.

 

[jimlay]

Yep!

Yes Peggy--the senders are in the tanks.

Jimlay

 

[Phil Herring]

The Wema's of that era are notorious for their sensors. If I recall correctly this is a mechanical problem with the sensor, not an electrical issue in the system. but then again, I'm getting older and my recollection may not be so good.

 

[Don12364]

I have them on my boat and have repaired one of the sensors twice since new in 1996. Mine are 450 mm long.
To Test:-
a) Measure the resistance and alter the level in the tank significantly either draining or refilling and re-check the resistance.
Or
b) Remove the sensor and inspect and move the float whilst measuring the resistance.

Wema Gauges have a float which moves up and down on a central rod. The float carries a magnet and inside the rod are a series of latching reed switches. A very neat design concept. I made a drawing of the system for future reference.
As the float travels up and down the rod the overall resistance changes and this is detected by the meter.
Max resistance for my sensors is 176 ohms and min zero or 22 ohms I cannot remember which.
Longer or shorter gauges may have different numbers of resistors of different values but I would still expect the same max and min values as above so the meter would suit all sensors.
Please see attached diagram.

I have had two problems since new in 15 years.
1) The magnets inside the foam float rusted and grew so jamming the float. Repaired and re-epoxied the insides of the float.
2) In the bow fresh water tank, after a very rough 8 hour beat to windward with a ¼ full tank, the free surface effect of the water sloshing caused the plastic rod to fracture.
Eventually I replaced that sensor with the stainless version which is more robust and, I believe, now has ceramic magnets that do not rust.
Since then - perfect.

 

[seadaddler]

DONALEX said it

Either your hunter manual or wema web site or call wema for the info to check the sensors resistance,that's what I did to check my waste tank sensor.
Nick

 

[dday49]

I have a 1998 Passage 450. If your multifunction guage says Wema Norway be aware that your three water tanks and your fuel tank use European sending units. The two holding tank guages use American sending units. Wema has an excellent trouble shooting section on it's website and excellent telephone support as well. I couldn't tell from your post if your guages are reading empty all the time (or full). But my water tank guages sometimes will stick and read a partial tank even though they are actually empty. I found I could "fix" them by by filling the tanks about half full and anchoring in a location with lots of wakes from other boats. The constant boat rocking from wakes works the floats and they return to correct operation. If none of your guages are working I would first check to see if they are getting power after throwing the circuit switch labeled "guages" on your electric panel.

Don

 

[jimlay]

All;

Thanks for the advice--the Wema panel does say Wema Norway on it.

The panel registers nothing when first turned on, then after 15-20 minutes all tanks indicate full regardless of the amount of fluid in the tank. This is what I find most confusing about the whole thing. I know that the tanks are full right now, but can't tell when they are empty.....

I'll try the ohmeter and see if I can differentiate between the panel and the sensor output.

Thanks

Jimlay

 

[sole pleasure]

Jimlay, All is correct. 1996 they used crap parts from WEMA. They new parts are metal, much better. I did my holding tank and water tanlk last year. I think each unit cost me approx. $20. They are pretty easy to replace.
Sole Pleasure

Greetings all;

I have a tank indicator that is wired to all 3 of my fresh water storage tanks as well as the diesel fuel tank. It hasn't worked since I bought the boat and it's time for me to troubleshoot. If you all wouldn't mind, where/how do I check the outputs from the in tank sensors (I have a voltmeter) to make sure that they are working properly? What would be the best way to go about figuring out what pieces/parts need to be replaced, refused or otherwise reset to make the system work for me? I know that the indicator panel is WEMA......don't yet know manufacturer for the sending units.

The boat is a 1997 Hunter 450 Passage.

Thanks

Jimlay

 

[Dennis Ferriello]

The Wema I recommend with my panel the Profile 8 tank or the Solo panel, since we don't make a Diesel fuel sender is the Wema.
Most of there units are the same: - Standard SAE 5 hole patterns, 2.125” bolt circle, 240 – 30 ohm operation.
After the first of the year we will be coming out with a 30-240 ohms rod sensor just like the one we have for water and waste that is now 0-5 volts. It will be a sealed PVC rod with no moving parts to worry about. Also we will be coming out with a Capacitance Diesel Fuel Sender, again no moving parts which will work with the WEMA VDO gauge and others.

Thanks

Dennis Ferriello
www.ferriellosales.com

dennis@ferriellosales.com

 

[Island Girl 34]

Sign me up!

The Wema I recommend with my panel the Profile 8 tank, since we don't make a fuel sender is the Wema.
most of there units are the same: - Standard SAE 5 hole patterns, 2.125” bolt circle, 240 – 30 ohm operation.
After the first of the year we will be coming out with a 30-240 ohms rod sensor just like the one we have for water and waste that is now 0-5 volts. It will be a sealed PVC rod with no moving parts to worry about.
Thanks

Dennis Ferriello
www.ferriellosales.com

dennis@ferriellosales.com

Dennis,

Sign me up for two of those! Let us all know when they are avaiable!

Ken

 

[Dennis Ferriello]

Ken:
Will do. We had been thinking about it and decided to go for it.
I will have our engineer get on it and will put you on the list.
In fact send me an email stating you are interested and anyone else who reads this do the same. I will start a list and those on the list will receive the rods first.
I will also have a sale price on the rods for those who sign up before it comes out.


Thanks so much for your interest

Dennis
www.ferriellosales.com
dennis@ferriellosales.net