Fuel sender/ gauge troubles

**KIRCHNER** · 02-23-2021, 04:18 PM

Bought 2 new fuel gauges, 2 new senders for my twin tanks. senders ohm @ 33-240 ohms. turn 12v on, gauges show 0 life. move float arm to full, gauge only shows 1/2. Faria tech said 33-240 ohm correct sender specs. whats up? new crimp conn. with key on, gauges remain bottomed out, below E. i guess ill test the other side, moving the float arm up/ down. thinking ill have the same result. seens the ohm range is out of wack??? im stumped.

**JR IN JAX** · 02-23-2021, 04:32 PM

Originally Posted by KIRCHNER

Bought 2 new fuel gauges, 2 new senders for my twin tanks. senders ohm @ 33-240 ohms. turn 12v on, gauges show 0 life. move float arm to full, gauge only shows 1/2. Faria tech said 33-240 ohm correct sender specs. whats up? new crimp conn. with key on, gauges remain bottomed out, below E. i guess ill test the other side, moving the float arm up/ down. thinking ill have the same result. seens the ohm range is out of wack???

Is it possible that you have a voltage drop/low voltage going to the senders? A 50% drop will cut the return signal by half. I have quit using the tank sender in my boat since I always had an Air Craft type Floscan meter/Totalizer installed. Since I switched to the 300XS and added the round MercMonitor, I always know exactly how much fuel was burned.

**KIRCHNER** · 02-23-2021, 04:47 PM

should i have 12v at sender, somewhere in the full/ empty range? yes, range is about 1/2 hull truth says no 12v at sender, sender uses variable ground. getting a little above my pay grade now. best i test the other tank/sender/gauge, see if i get the same 1/2 tank reading. they have separate grounds, but jump from other gauges at dash???

**FUJIMO** · 02-23-2021, 07:57 PM

...you ran a 12 volt positive wire to the swing arm sender on top of the tank?...

**KIRCHNER** · 02-23-2021, 08:37 PM

No, no. Spent all day, checking, senders,gauges, wiring. everything checks good. gauges say 3/4, put tanks are full. im done! after researching, lots of feedback, ive concluded float arm gauge/ senders just suck,period. 90% dislikes, with no real cure. hope my sharpie works lol.

**flabum1017** · 02-27-2021, 09:29 AM

Grounding of the tank is always a problem..... make sure you have a sender wire AND ground wire going from the sender straight to the gauge. If you use the boat ground to the tank, you end up with enough resistance that will cause the problems you have. Still, leave the bonding wires on the tank and make sure you have a bonding wire going from the tank to the fill if the fill is metal.

**FUJIMO** · 02-27-2021, 11:50 AM

...what bum said... (the ground/bonding wire from the tank to the fuel fill that bum mentions, is for the elimination of static electricity buildup created from the fuel flowing/racing down the rubber 1 1/2" fuel fill hose during fill-ups, that creates static juice) ...then of course, the separate ground wire directly to the gauge as he said. a length of 14 gauge is fine for both.

**RSWORDS** · 02-28-2021, 07:51 AM

Ground the sender wire at the tank. If your needle pegs at full. Wiring and gauge is good, sender is **** (get a Reed style) if it doesn't peg go to back of gauge and ground the sense wire. If gauge pegs, the wiring is bad, if doesn't pegs gauge is bad.

**flabum1017** · 02-28-2021, 08:21 AM

Originally Posted by RSWORDS

Ground the sender wire at the tank. If your needle pegs at full. Wiring and gauge is good, sender is **** (get a Reed style) if it doesn't peg go to back of gauge and ground the sense wire. If gauge pegs, the wiring is bad, if doesn't pegs gauge is bad.

That's not reliable if there is resistance in the wiring.... resistance in the wiring will make the gauge inaccurate. Grounding the sender wire is a quick way to tell if you have a cut in the wire or a dead gauge. but when you have a gauge reading half full when the tank is full, then you have resistance between the tank and gauge (or the float is hitting something inside the tank), the sender out of range or the gauge is not reading proper. Usually if the gauge isn't showing the proper level, it means it does not have a ground wire going directly from the sender to the gauge. The best way to test the gauge/sender combo is to bring the sender up to the gauge, hook the sender up to the gauge with short wires and raise and lower the float to see if it is accurate.

**KIRCHNER** · 03-13-2021, 07:53 PM

after all the hassle, wiring, connectors and frustration, i had 2 defective new gauges, calibrated wrong, must have made on a fri. afternoon. also a well known brand.

**WaterZebra** · 03-14-2021, 12:39 PM

Originally Posted by KIRCHNER

after all the hassle, wiring, connectors and frustration, i had 2 defective new gauges, calibrated wrong, must have made on a fri. afternoon. also a well known brand.

Your first mistake was buying Faria.............

**FUJIMO** · 03-14-2021, 03:32 PM

...bought thousands of new "marine" gauges for new builds, from all the major venders. gaffrig, livorsi, faria, stewart warner, mercury, teleflex, beede, auto meter...they ALL have issues. probably the most trouble free were the mercury quicksilver stuff. hard to believe, i know...