Thread: TD5 Fuel Gauge failure

What vehicle are we asking about? Series1 Land Rover, D3 Disco ???

Erich

Originally Posted by Bundalene

What vehicle are we asking about? Series1 Land Rover, D3 Disco ???

Erich

Sorry - Its an 01 TD5 130 Defender.
My bad...

Are you certain it is not the sender? I have just replaced 1 with identical symptoms, to check it I just unplugged the connector from the fuel pump (Thankfully it was a trayback) and plugged it into another tank unit I had, gauge was fine. On examination, the coil had worn through on the sender where the contact rubs up and down across it.
I replaced the complete pump assembly on this one as it had done 150K already.
Another cause is the gauge sender unit itself falling off the side of the pump assembly they are clipped on, and sometimes they just 'unclip' and drop off. (Pretty hard to do, looking at the clip arrangement but it has been seen before)

JC

The fuel gauge in the tank has a float which moves a slider up and down a pot (variable resistor). Is it possible that the float has a leak or the resistor isnt working correctly.

If that is the case I have a spare which you are welcome to try - the gauge itself unclips off the pump, but the wires have to be cut and re-soldered - re-insulated.

The biggest drama with a Defender is disconnecting the fuel lines to remove the tank to check this.

Erich

My testing involved removing the power plug and measuring the pins themselves - 0.27 Ohms. This tells me that there is just under 1/2 a tank left, which I confirmed using a recently replaced pump.

The current pump and sender are about 4 months old.

I measured the same .27 ohms all the way to the back of the speedo. I will be doing some driving and re-testing, as it may well be broken. I just assumed that it was a valid resistance as I replicated it on another pump.

Cheers

Fraz,

You can unclip the wiring loom to the pump enough to hang it out into the drivers rear wheel arch, connect the other pump assembly you have and try the gauge unit float and arm up and down.

JC

Originally Posted by justinc

Fraz,

You can unclip the wiring loom to the pump enough to hang it out into the drivers rear wheel arch, connect the other pump assembly you have and try the gauge unit float and arm up and down.

JC

Thanks for that one, Ill try it tomorrow morning. It never occured to me to pull it out the drivers side - i did think about the other side though. Not long enough

D'oh!!!!

Originally Posted by Fraz

My testing involved removing the power plug and measuring the pins themselves - 0.27 Ohms. This tells me that there is just under 1/2 a tank left, which I confirmed using a recently replaced pump.

The current pump and sender are about 4 months old.

I measured the same .27 ohms all the way to the back of the speedo. I will be doing some driving and re-testing, as it may well be broken. I just assumed that it was a valid resistance as I replicated it on another pump.

Cheers

Fraz
I know this a year or so old but I have a 2000 Defender with new pump and no functioning fuel guage.

What was the final result with your investigations.

I have 130 l of Diesel in tank and guage is on top of orange, ie about 1/4 of full scale.
I filled up with high flow pump because the low fuel warning light came on.
Have measured 26 Ohms across sender from the fuel guage end. guage was stuck before I used high flow truck dispenser.

Help any ideas? Don't relish pulling out tank again because no access from top due to tray design.

regards Peter L.