2007 H31 Wema water gauge

Jun 25, 2005
72
Hunter 31 Carlyle IL
Wema water gauge not working. There is power to the gauge as it lights up when the breaker is on. Can't figure out how to access the sending unit on top of the tank. The water tank is under the forward V berth but after removing every wood screw that I can find on the platform where the mattress lays on the panel will not budge.
 
Dec 19, 2006
5,809
Hunter 36 Punta Gorda
Try

Try going to Wema web site and see how to test tour senders and system or call for help.
For both to stop working check at the gauge for bad connection.
Do you have the round gauge.
nick
 
Jun 25, 2005
72
Hunter 31 Carlyle IL
Nick,,, you bring up a good point. I purchased the boat pre-owned last year. Less than 200 hours on the engine I am very happy with the vessel after my first season with her. There are very few discrepancies. I also have all the manuals and wiring diagrams but nothing to show how to switch the gauge (which is round by the way) to show separate tanks. I just guessed that it is for the water tank quantity only. If there is a transfer switch to another tank than I have not found it.
 
May 18, 2017
66
Hunter 44 Changes
We are having a similar problem but all 3 WEMA water gauges are out....they did not stop working at the same time but after reviewing this post, I'm assuming it's a connection issue not 3 non-working sending units. Would you agree?
 
Jun 4, 2004
834
Hunter 340 Forked River, NJ
I had a defective WEMA water tank sensor on my 2000 H340. I could not find a suitable replacement match on the WEMA web site so I contacted them at info@wemausa.com. It turns out that the Hunter factory installed water tank sensor on my boat (marked 01-00, W2-17-H336) is a now discontinued model and has been replaced with the WEMA S3 series. This is a 0 to 180 ohms sensor and is 17 inches long. Curiously, the unit on my boat is a round, European, screw-in sensor which is mounted in a standard five-hole American style adapter ring. The gauge-compatible replacement for my boat is the European sensor # S3-432.

I had to deal directly with customer service at WEMA via email and phone and they were very helpful. As it turns out, you cannot purchase the new S3 sensors from the web site. The online sensors look the same but the ohms are different. The ones on the website are 240 ohms at empty and 33 at full. The replacement sender I need is 0 at empty and 180 at full. If you order online, you will need the entire system (gauge + sender) to make sure the units are compatible. I had to order my new sensor by phone directly from WEMA. Their contact number is on their web site.

I ordered a new sensor and unscrewed the old one from the mounting ring. The Hunter factory sealed the threads with some unknown caulking so I used a hot air hair dryer to soften the caulking and the sender unscrewed without any problem. There are only two wires to reconnect. Of course, this only works if you cvan gain access to the sensor under the wooden panels.
 
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
The 0-180 ohm is the European standard. The 33-240 ohm is the American standard. American gauges work with American senders. European senders work with European gauges. If you mix & match, they sort of work backwards, but are not accurate.
 
Oct 22, 2014
20,989
CAL 35 Cruiser #21 moored EVERETT WA
Speculating here..
If I hook up the USA sensor to the European gauge, the unit will peg 0. Which would mean the polarity is backwards. So I reverse the polarity and the then the gauge would indicate half full when it really is full?
 
Aug 22, 2017
1,609
Hunter 26.5 West Palm Beach
This is off the top of my head from a long time back, so take it with a grain of salt. I think that the direction of change in ohms is backwards between the European & the American versions. I think that one is high ohms at full tank & the other is low ohms at full tank. Please look this up & confirm that it is true before relying on this information. It's late & I'm too lazy to look it up right now.
 
Dec 19, 2006
5,809
Hunter 36 Punta Gorda
There should be a toggle switch on bottom of gauge to switch from water to waste.
Nick