Diagnosing a Faulty Fuel Gauge

Bay Stealth

Cadet
Joined
Dec 30, 2004
Messages
15
I have a fuel gage on my boat that when you turn the key on it goes slightly up then all the way down. I have a good ground and get power to both terminals on the back of it when the power is on. I cleaned all the terminals on it and on the sending unit and seem to have power and ground where it needs to be. I haven't metered the terminals on back of the gauge because I don't know the values they should be. I feel I have a bad gauge but want to check with you guys first to see what you think. Thanks alot!
 

snapperbait

Vice Admiral
Joined
Aug 20, 2002
Messages
5,754
Re: Diagnosing a Faulty Fuel Gauge

Don't know what the ohm values of the gauge should be.. sorry..<br /><br />Did ya check the ohms values on the sender? <br /><br />Between the ground and the terminal on the sender, you should be getting 35 ohms full, and 240 ohms empty... (+ or - a few ohms either way)
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: Diagnosing a Faulty Fuel Gauge

First a big welcome BS (I like the shortened version)!!!!<br /><br />Now to fuel gauge problems - outside of corroded connections the most common problem is the sending unit itself not the gauge. You can remove yours and test it by moving the float up and down and watching the reading on the gauge. They are not all that expensive to replace. You would probably spend as much replacing it as you would in terms of time checking out the current one. <br /><br />While you can get "generic" senders I would recommend that you contact the manufacturer of the gas tank (see the data plate mounted on the tank) and get the one specific for your tank. Because tanks come in all shapes and sizes I think you will get a more accurate reading this way. The mounting (size/attaching screws) is industry standard.
 

Bay Stealth

Cadet
Joined
Dec 30, 2004
Messages
15
Re: Diagnosing a Faulty Fuel Gauge

Thanks Snapper, I'll check it and see what I get and will let you know.<br />SoLittle, thanks for the welcome, I removed the sending unit and cleaned all connections real good. I was having a problem before with a terminal end. I guess I could put a meter on the gauge and manually move the gauge up and down and see what my reading is and also get the reading of what Snapper posted before. Thanks alot for the help guys!
 

gewf631

Chief Petty Officer
Joined
Mar 4, 2003
Messages
489
Re: Diagnosing a Faulty Fuel Gauge

Teleflex has some good info.<br /><br />Their FAQ's are here <br /><br />And their troubleshooting stuff is here
 

Terry H

Lieutenant Commander
Joined
Sep 25, 2001
Messages
1,862
Re: Diagnosing a Faulty Fuel Gauge

so bs, how did you fix the sending unit? Chief
 

Bay Stealth

Cadet
Joined
Dec 30, 2004
Messages
15
Re: Diagnosing a Faulty Fuel Gauge

Plopped down $25 and bought a brand new one. The previous owner of the boat is a good friend of mine and said it was the original unit and the boat is a 1996 so I think it was about time for it to go out.
 
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