level gauge for fresh water tank

[gmwalley]

I am trying to find a fault with the gauge for fresh water tank fill level. This is on a 1994 / 370 aft cabin. Gauge reads empty, pulled it out of panel in aft head, no power to the sensor. Power wire is orange and is labeled "L7" . This gauge / wiring appears no where is documentation from Carver, wiring diagrams, user manual, etc. Anybody know where meter power comes from?

[tomschauer]

Just happened to be trouble shooting mine this past weekend.
My 1998 355 has a tank monitor breaker. Seems 12v goes to sensor on tank first. Then to meter.
Sorry, don't remember the colors,
But I had 12v + 12v ground and signal (varies with level.) wires at the sender. All three then go to gauge. I had a bad gauge.
Does this help at all?

[gmwalley]

Don't know yet if it will help. I have a orange / black power at gauge with lavender? I assume going off to the tank. My tank is buried under the berth and is a pain to access. That was my next place to look. I turned on ALL the 12V breakers in the panel under the assumption power was coming from someplace weird. I even turned both ignitions "ON" - still no power. I think this means I have a bad splice somewhere - just hoping to have some help before I start taking the boat apart.

[SplashyLady]

There should not usually be power to the sender. Tank level gauges read resistance in the sender, and usually you will not find 12V at the sender. That could cause a spark if it shorted which might lead to a bigger boom. You can check the sender with an ohmmeter - it should read 30 to 200 ohms depending on how full it is. The sender is defective if you get a short (0 ohms) or an open circuit. I suggest a WEMA sender if you need to replace, but you can always go back to what was originally installed. Here is a troubleshooting diagram for Teleflex gauges - the same process basically works for fuel and water tanks: http://www.jamestowndistributors.com/us ... ?docId=833

Hope this helps - good luck!

[mjk1040]

Our 1998 355 AC/MY has the same unit, 12 volts in, 12volt ground and a sensor wire at the sender and the gauge. With a meter you should be able to read this. Our gauge quit last season, but started working again this spring, go figure. Most likely will have to pull the sensor and soak it in vinegar or CLR. Some where you have a break in the 12 volt feed wire, keep looking and trace it out, some one may have spliced into this wire some where and it corroded now thus no power, or it could be a original install connection that corroded, thus no power. When you find it and re-splice it, use some die-electric grease on the wire ends before you crimp them. Mike

[gmwalley]

Looking at gauge end - no power at all (orange wire marked L7) so know problem is not sender related. Have switched out fuel sending units to WEMA style and intermittent problems with those were resolved. Plan to swap out water tank sender also but can't get power to gauge resolved. Probably a bad splice somewhere!@#$!%. I'm an electrical engineer and AL state electrical contractor - so I would not have a hidden splice but never know what past sins previous owners committed.