The Stovebolt Site Forums The Shop Area The Electrical Bay fuel gauge

over the past few years,my fuel gauge would become erratic at times.I kept putting it off because i don't drive the truck everyday.Today i was at the local vendors and puchased a new sending unit for it.I installed the new one,and the gauge is working great now.I started looking over the old unit and dicovered the float has a hole in it.The hole is where the arm clips onto the float.I shook it and it was half full of fuel.I could have saved a little money just purchasing a float.I have a spare unit now and will get a float for it.If you guys are experiencing a gauge that shows 1/2 tank to full tank and the needle bounces,check the float on the sending unit,it could have a hole in it.

Thats what happened to mine. I bought a new float and it works fine. Here's a tip I found latter. If you can't find a float use a wine cork it's supposed to work.... Peter

I have seen old floats that were made of cork. i don't know if they were coated or not. brass floats can be repaired. or use any thing like a pill bottle or cork or cannibalize a newer unit.

They sell the original brass type for $5.00 from most vendors.Mine is worn really thin where it clips on.I have considered soldiering it,just have'nt tried yet.

Wouldnt the gas eat up the cork or soak into it making it heavier? Id try and solder the old one first.

I have a 1961 boat gas tank with a cork float still works fine

I tried soldering mine but you have to get all the holes the pill bottle trick sounds good

Well for $5 go for a new one why waste your time.

I've already replaced the unit with a new one. Why waste my time ? For the challenge,to see if i can .If i ruin it,i'll throw it away and buy a new one.

This may be a naive question, but it comes from someone who is electon challenged. My fuel guage doesn't work either and I don't know what part of the system is faulty. If I pull the sending unit and lift up and down on the float arm, should my dash guage show full or empty if it's the system is working?

Yup, but it needs to be grounded when you do that

Rusty 54,

There are two components that have to work for the fuel gauge to function.

If you actually have power to the gauge, try this. With the key ON, pull the wire off the sending unit. The gauge should show FULL...

Now take the same wire and touch it to a good ground. The gauge should show EMPTY...

If this procedure works, it means the wire from gauge to sending unit is good, and it means the gauge is working.

This puts the blame on the sending unit (or its ground). These are usually just replaced..not repaired. Do some testing and see what develops.


Stuart

Stuart,

Thanks, very helpful. The guage reads empty. If I detach the lead wire, no change. If I touch the lead wire to a ground, the guage pops to full. Do I have something crossed up, probably on the back of the guage?

Rusty 54,

I'm not sure. Because the gauge reacts to the tests at the tank, it tells you the wire is good, and the gauge is functioning.....just backwards. I sure as heck would switch wires on the back of the gauge and see if that makes things proper.

Keep us posted...interesting.

Stuart

Rusty 54,

Is your truck a GMC? If it is, are you running it negative ground rather than positive? If so, that could explain the wiring of the fuel gauge.

No, it's a chevy and all the wiring seems to be hooked up right. I'll have to tinker around with things to see what works. Thanks for the suggestions.

All the rigs I've worked on, ground the wire from the sending unit, the gauge should read full. Sounds like your wire and gauage is working fine.