Fuel level sender

Since my rebuild of my 1992 200tdi 90 my fuel tank has said it's full. It's fairly full, but I'd imagine 3/4s full.

I took the new sender out today and it seems to be working backwards. If i lift up the arm, the fuel gauge goes down, if I let it down it goes up.

I thought I'd fitted the wires right, there's two wires. One that is black and goes to an earth point on bulkhead, then a green and black which goes to the gauge. There's three connectors on the fuel level sender and I've tried each wire in each connector.

I'm pretty sure it's the right sender, and the game was working ok before. I've checked the earth and it seems to be good.

Any ideas?

gse1986 said:

Since my rebuild my fuel tank has said it's full. It's fairly full, but I'd imagine 3/4s full.

I took the new sender out today and it seems to be working backwards. If i lift up the arm, the fuel gauge goes down, if I let it down it goes up.

I thought I'd fitted the wires right, there's two wires. One that is black and goes to an earth point on bulkhead, then a green and black which goes to the gauge. There's three connectors on the fuel level sender and I've tried each wire in each connector.

I'm pretty sure it's the right sender, and the game was working ok before. I've checked the earth and it seems to be good.

Any ideas?

Click to expand...

One wire is for low level fuel light, try googling it for how to connect them up

Bend the float arm a bit.

The issue is that it is responding backwards - surely the arm should go up and raise the fuel level, and go down and drop the fuel level - this is going the other way around.

Mine only has ever had two wires - rather than having an extra for the low level light too.

The item I ordered was STC1139 - which i believe is 1984-1998

Aahh, right- sorry, speed read your post and missed that bit.

Clutching at straws- wires wrong at gauge? I can't see how that can happen unless the thing has been made wrong.
The sender alters the ground resistance to the gauge as I understand it, your getting more resistance when you need less and vice versa.. will it fit upside down? Been a long time since I built my Defender, 14yrs, and I don't recall if the sender plate is keyed to aid positioning.

It could be the gauge and sender had been replaced before I bought the vehicle....the two senders looked the same, the old one didn't change resistance at all, hence why I replaced it.

The sender itself can't really be fitted upside down as it has a plate that goes into the fuel tank on top.....if it was upside down the plate would have to be in the fuel and nothing would seal the hole

I've had one other thought.....I had an issue with my temperature sensor the other week since rebuild....it was over reading. My understanding, though I can't find any definitive information is the gauges work at 10volts rather than 12....presumably this needs some sort of transformer. Could it be that the transformer is knackered and throwing the fuel gauge and the now replaced temp gauge? (Temp gauge is now mechanical so power isnt an issue anymore....)

I'm pretty sure voltage regulators weren't fitted after the series 3 . Can you get gauge wires the wrong way round?
Try removing the gauge, disconnect the existing wiring at the sender and wire it direct to a battery to eliminate any weirdly goings on with the existing wiring?

The gauge wires I don't think can be the wrong way round - if i remember there's one male and one female blade connector on the back, and corresponding female and male connectors in the loom.

I will try and wire a direct wire and see what I get.

The sender is keyed and so can not be fitted the wrong way,wiring can be fitted wrong on tank as all are spades.On my 1990 90 starting from the rear it's black,white green.