I ran into this and thought is np might be of interest to the list. Seems like an attractive price.
http://sbo.sailboatowners.com/index.php?option=com_adsmanager&Itemid=283&page=showad&adid=16526 Tom Buscaglia S/V Alera 1990 C&C 37+/40 Vashon WA P 206.463.9200 > On Apr 5, 2015, at 9:00 AM, cnc-list-requ...@cnc-list.com wrote: > > Send CnC-List mailing list submissions to > cnc-list@cnc-list.com > > To subscribe or unsubscribe via the World Wide Web, visit > http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com > or, via email, send a message with subject or body 'help' to > cnc-list-requ...@cnc-list.com > > You can reach the person managing the list at > cnc-list-ow...@cnc-list.com > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of CnC-List digest..." > > > Today's Topics: > > 1. Re: Problem with 2 new fuel gauges...long story (Don Newman) > 2. Re: Problem with 2 new fuel gauges...long story (Robert Boyer) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Sun, 5 Apr 2015 09:19:42 -0400 > From: Don Newman <donrnew...@gmail.com> > To: Robert Boyer <dainyr...@icloud.com>, "cnc-list@cnc-list.com" > <cnc-list@cnc-list.com> > Subject: Re: Stus-List Problem with 2 new fuel gauges...long story > Message-ID: > <CAPLAmt5N8nAyQzbqjqBJBUR=rq6YjqCWc_R=vyoz9hsnzuq...@mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > The actual meter portion of analog meters are essentially the same (Volt, > Amp, Ohm) they register the voltage presented to them. The way the are > placed in the circuit makes the difference. Volt meter across the voltage, > Amp across a shunt (a low resistance resistor) to measure the voltage drop > across the shunt and Ohm has its own power supply to measure resistors. > > The normal setup for fuel tanks is for the meter to be supplied with the + > voltage and one side of the the variable resistor in the tank connected to > the meter and the other to ground. In the case of a metal tank such as in > an automobile the tank itself is grounded so there is no need for a second > lead. If the tank is plastic then a ground lead is needed to the frame of > the sensor assembly. > > If there is no connection to ground then the meter should not move. > > You said you measured the resistance across the sensor on one tank. Is > this the one you think is failing? > If not you can measure the sense line to ground to check the resistance on > the one you think is failing. > If it is the new tank that is failing are you sure that on the tank sensor, > one side is connected to ground and the other to your meter? > > You could try to find something in the 100 ohm range to test the meter - > light bulb etc. > > Good luck. > > Don Newman > C&C 44 > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://cnc-list.com/pipermail/cnc-list_cnc-list.com/attachments/20150405/513ff167/attachment-0001.html> > > ------------------------------ > > Message: 2 > Date: Sun, 05 Apr 2015 09:22:10 -0400 > From: Robert Boyer <dainyr...@icloud.com> > To: Josh Muckley <muckl...@gmail.com> > Cc: C&C List <cnc-list@cnc-list.com> > Subject: Re: Stus-List Problem with 2 new fuel gauges...long story > Message-ID: <d9123450-2cfc-47ed-97d5-50b2ed085...@icloud.com> > Content-Type: text/plain; charset="us-ascii" > > One terminal of the sender connects to the plate that mounts to the > tank--this is grounded because the tank is grounded. So, polarity is > involved here. I can remove the tank ground and switch the wires. > > Bob Boyer > S/V Rainy Days / Annapolis MD > 1983 C&C Landfall 38 - Hull #230 > email: dainyr...@icloud.com > blog: dainyrays.blogspot.com > > "There is nothing--absolutely nothing--half so much worth doing as simply > messing about in boats." --Kenneth Grahame > >> On Apr 5, 2015, at 1:06 AM, Josh Muckley <muckl...@gmail.com> wrote: >> >> The sender doesn't have a polarity. It is just a resistance. Is this what >> the back of your sender looks like? Which wires do you have attached where? >> >> Josh >> >>> On Apr 4, 2015 10:49 PM, "Robert Boyer via CnC-List" >>> <cnc-list@cnc-list.com> wrote: >>> When you connect the sensing wire to ground, the needle goes positive all >>> the way as it should do but it does not register the fuel level. >>> >>> I now believe that one gauge is working correctly because the needle moved >>> slightly positive when energized--but the tank is completely empty. >>> >>> The other gauge is hooked up the same way but I think the wires inside the >>> tank sender is reversed, which makes the needle go in the wrong direction. >>> I remove the ground from the sender and reverse the sender polarity >>> tomorrow. >>> >>> Wal, would I also have to reverse the power supply polarity on the gauge to >>> make it work properly? >>> >>> Thanks! >>> >>> Bob >>> >>> Bob Boyer >>> S/V Rainy Days / Annapolis MD >>> 1983 C&C Landfall 38 - Hull #230 >>> email: dainyr...@icloud.com >>> blog: dainyrays.blogspot.com >>> >>> "There is nothing--absolutely nothing--half so much worth doing as simply >>> messing about in boats." --Kenneth Grahame >>> >>>> On Apr 4, 2015, at 10:40 PM, Marek Dziedzic via CnC-List >>>> <cnc-list@cnc-list.com> wrote: >>>> >>>> Josh, >>>> >>>> This is certainly not sailing related, but if i remember it correctly, >>>> they are all really ammeters (the current flowing through them creates the >>>> magnetic field that moves the needle). >>>> >>>> Marek >>>> >>>> >>>> >>>> Josh Muckley via CnC-List wrote: >>>> >>>> >>>> All analog meters are just measuring the "voltage drop" across a >>>> resistance. The key is to have the appropriate voltage input +12v. If >>>> the +12v and the sensing line were reversed then the "voltage drop" would >>>> be "negative" driving the needle to the empty peg. >>>> >>>> Josh >>>> >>>> On Apr 4, 2015 7:08 PM, "Wally Bryant via CnC-List" >>>> <cnc-list@cnc-list.com> wrote: >>>> I thought they were Ohm meters. Anyway, I just Googled it to make sure, >>>> and see a ton of pages on testing marine fuel sender resistance. >>>> >>>> Wal >>>> >>>> you wrote: >>>> I agree with your diagnosis. It's gotta be reversed polarity...of the >>>> sense and gnd. Fundamentally the fuel gages are just voltage meters. They >>>> respond proportionally to the voltage drop across the variable resistance >>>> in the sender. I would disconnect the leads and use an ohm meter to >>>> measure and validate the resistance of the senders. Switching the polarity >>>> of the sense and gnd monetarily probably won't break anything. Before >>>> doing so validate that your wiring looks like the attached picture. >>>> >>>> >>>> _______________________________________________ >>>> >>>> Email address: >>>> CnC-List@cnc-list.com >>>> To change your list preferences, including unsubscribing -- go to the >>>> bottom of page at: >>>> http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >>>> >>>> _______________________________________________ >>>> >>>> Email address: >>>> CnC-List@cnc-list.com >>>> To change your list preferences, including unsubscribing -- go to the >>>> bottom of page at: >>>> http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >>> >>> _______________________________________________ >>> >>> Email address: >>> CnC-List@cnc-list.com >>> To change your list preferences, including unsubscribing -- go to the >>> bottom of page at: >>> http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com >> <$_3.JPG> > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <http://cnc-list.com/pipermail/cnc-list_cnc-list.com/attachments/20150405/0fcc6c55/attachment-0001.html> > > ------------------------------ > > Subject: Digest Footer > > _______________________________________________ > CnC-List mailing list > CnC-List@cnc-list.com > http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com > > > ------------------------------ > > End of CnC-List Digest, Vol 111, Issue 11 > ***************************************** _______________________________________________ Email address: CnC-List@cnc-list.com To change your list preferences, including unsubscribing -- go to the bottom of page at: http://cnc-list.com/mailman/listinfo/cnc-list_cnc-list.com
