Did I break the fuel sender?

[NiGMa]

Hey guys,

So I thought I'd fix this little gizmo the other night. The problem with it is that it is a bit crazy, when I fill the tank up to full, it shows it as 80% full, but then every now and then goes down to Empty.

I think I understand how it works. I know its some kind of variable resistor circuit. So I took it out of the car and checked it with the multimeter, as expected the resistance(ohms) measured was erratic as I moved the float arm back and forth. So I figured the contact arm on the winding of wire must not be connecting well, so I sanded it a little and put some di-electric grease(bulb grease, its the same right?) on it. Checked it with the multimeter and it showed smooth ohms from 150ohms at empty and ~8-15ohms at full.

So I put it back into the car and guess what?

It just shows Empty and doesn't move from there in the slightest.

How did I brake it?

Does anyone know what the correct ohms are for it at each end of the arm swing?

Does your car also have a crazy fuel guage after 20+ years?

Did you fix it better than me?

 

[ValgeKotkas]

Yes! Same here. Though it sometimes goes up, and a little above E it starts showing the ''real thing''.

 

[3p141592654]

Reading E means an open circuit.

Pull the plug at the sender and measure the resistance across it. If it is open circuit then you will have to pull the sender and figure out what happened. If its reading correctly (10-150 ohms) then the problem must be in the gauge circuit. I would start by checking the sender connector for problems (bent pin, corrosion, etc).

By the way, the dielectric grease seems like a bad idea. Its going to get washed by the gas and presumably dissolve.

 

[WhtMa71]

You must bend the little arm in towards the coil so that it contacts it thru the whole F-E range.