Fuel gauge not working

Rocko · 11-09-2009, 08:00 PM

I have a 21 ft northriver scout with in floor fuel tank the boat is a 2003. The gauge stoped working this summer. I put in a new gauge and it still dose not work. I also pulled the floor to check all the wireing and can't find anything wrong how do you test the fuel float setup.

adobe wall · 11-09-2009, 08:15 PM

Quote:

Originally Posted by Rocko

I have a 21 ft northriver scout with in floor fuel tank the boat is a 2003. The gauge stoped working this summer. I put in a new gauge and it still dose not work. I also pulled the floor to check all the wireing and can't find anything wrong how do you test the fuel float setup.

I'd say run a fair amount of fuel out of the boat then check the resistance on the sender harness with a meter. It will chance with the change in fuel. You can tilt the trailer up or down with the tongue jack.

FWIW, may be nothing more than how the tank and sender is oriented. I know some scouts have the tank at 90 degrees to the centerline of the boat, up in the front. That may work. If the tank is in the floor and is oriented with with the centerline of the boat you won't get a fuel gage to read anything other than full until the tank is heading towards empty. Dumbest thing in the world. My boat's tank sender is at the back of the tank, tank mounted in the floor, so all the fuel is going to stay at the low end (rear) of the tank until it's out of gas. I just fill the boat before every trip. A flow meter is a much better alternative but those are spendy.

aw

Rocko · 11-09-2009, 08:25 PM

The fuel float is in the back of the tank and never worked good until you were at a complete stop but it did work and now it dose not work at all

adobe wall · 11-09-2009, 09:43 PM

Quote:

Originally Posted by Rocko

The fuel float is in the back of the tank and never worked good until you were at a complete stop but it did work and now it dose not work at all

Then unplug it and check the resistance with a multimeter. You can check at the switch.

Could be a bad sending unit, bad wire, bad switch, or bad connection at any of the above, will take a meter to figure that out. Sounds like mine, which wasn't worth the trouble to figure out.

aw

KingSalmonBoy · 11-10-2009, 04:56 AM

Resistance between unconnected terminals at sender should be from 33 to 240 ohms.

packer · 11-10-2009, 07:40 PM

quick check for the gauge take the sender wire off and ground it out ,the gauge should go to full ,if it doesn,t you have a wiring problem

mstarck · 11-10-2009, 08:38 PM

Rocko, to test the sending unit (fuel float) you will need a ohm meter.if you don't have one they are available at any hardware store.$10.00 or less.they come with instructions.Iwould remove the sending unit from the tank.the unit might be marked as to the ohm range it works in example 240 to 33 ohms.it could be marked on the unit.first off i would check ground and sender wire end to end with ohm meter.but the question was how to test float.hope that helps.BTW the fuel gauge in my new TJ was defective when i took delivery and turned out to be the sender(been there done that)so good luck to you.

mike

mstarck · 11-10-2009, 08:48 PM

heres a pic of the unit out of the TJ.

Rocko · 11-24-2009, 06:15 PM

Thanks for all the info now i have some place to start to fix it

Fishnchips · 11-25-2009, 12:35 AM

I have seen sending units mounted wrong in the tanks. Most of them have about 6 bolts attaching the flange to the top of the tank and you can "clock" it just about any way you want. If it is the lever float setup (like a toilet) it must be positioned so the float doesn't swing into the inside of the wall.

Either way, you can test the sending unit by checking resistance across the terminals (with the boat wiring removed from the circuit). While you have the meter leads attached, rock the boat side to side and see if the meter readings change. I like the cheapy analog meters for this because you get a nice needle movement that you can see.

If the needle doesn't swing back and forth like the gas sloshing inside, remove the sender and move it the full swing and check for smooth needle motion.

Tony Fox · 11-28-2009, 02:32 PM

Quote:

Originally Posted by packer

quick check for the gauge take the sender wire off and ground it out ,the gauge should go to full ,if it doesn,t you have a wiring problem

Do exactly what Packer said! Especially if you have already changed the sending unit. Gauges are sometimes the culprits. Salt water can also do strange things to your wiring, up through the shielding,(not just the connections).

Bloomy · 11-29-2009, 06:02 PM

Have the same boat and had the same problem this summer. Changed the gauge, didnt work, put a new sending unit in and problem solved! They are only like $20 bucks and I just googled the model number and ordered one.

Good luck

Hevyduty · 12-26-2009, 09:10 AM

My fuel gauge is not very accurate and I don't care. Do yourself a favor and get yourself a floscan or other quality fuel flow meter. I've used them for years and realy like knowing EXACTLY how much fuel I have left. Knowing how much fuel is remaining and your burn rate can tell you if you are going to make it back to the ramp or if you need to change your speed or load distribution.I installed one in the boat I bought last spring before I even put it in the water. I will never own another boat without one

There but for the grace of god go I.