Strange fuel gauge issue

Very strange one here.....

For the last year or so my gauge has wondered a bit and so just before Christmas I decided to just get a new sender. On arrival I found that my fuel tank has been changed from the normal 1995 tank to the earlier one where the sender is held in place with a mechanical collar. Anyway swapped the new sender and fitted it and it worked fine other than showing a generally lower level than the old one (just needs the arm bending to the right place).

Right that was 2-3 weeks ago and today I got back into the Landy whilst out and the fuel light was on and the gauge was showing empty. I checked for leaks (I put £30 of diesel in a couple of days ago and only did about 15 miles). No leaks. Lifted the seat and dis-connected and re-connected the two electrical wires - nothing. Removed the fuel line and undid the collar then popped out the sender. Holding the sender and moving the float manually the gauge goes from empty to full and back. Refitted the sender - not working. Took it out again and it worked. Refitted and it didn't. Checked diesel level and drove home with gauge showing empty.

When home removed the crimps and fitted new ones just in case it was a loose crimp - no change. Took out the old sender and fitted it - works! Swapped back to the new one - doesn't work!!!

OK only thing I could think of was a leaking float..... Swapped floats and the old one still works new one doesn't but DOES work if out of the tank and moved manually. Refitted the old one and it still works......

WTF!!

So we know:

Gauge works
Wiring works
no grounding issues/fuse problems etc.
Float is ok
New gauge works whilst out but not whilst in but did do for 2-3 weeks previously
Old gauge works just like it did and still does

Bizarre.

Is the movey bit making good contact on the slidey bit (electrical)?
Maybe outside the tank it is if it's being held a certain way it is but left to its own devices in the tank it isn't?
Can you bend the contacts so they rub together a bit better?
Don't know if that's even possible, I've done it years ago but it wasn't on a tratter.

Strangely it works in the same plane as it would be in the Landy but also sideways. The fact that it just suddenly failed makes it even more weird.

cowasaki said:

Strangely it works in the same plane as it would be in the Landy but also sideways. The fact that it just suddenly failed makes it even more weird.

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Have you tried turning it off and on?.............only joking
Is it worth trying it out of the tank but with a separate jumper wire between the locking ring point on the tank and the locking ring point on the sender (assuming they are metal obviously) just in case the sender has some odd internal insulation failure which is dragging something down. If it was working out of the tank and then doesn't with the jumper wire fitted it will be the bonding between the sender and tank that is causing he issue.

Its a poor connection issue very common on certain other vehicles

When you clamp it into the tank it probably warps a bit an the contacts are lost. As Flossie says try bending the contacts a little.

The contacts are on the upper and I've messed with them both. I switched it back and forth more than once and it worked faultlessly for 2-3 weeks prior to total failure. Very strange fault. I attached a jump lead to ground the tank out but no difference. It's working with the old sender without fault now. I'll have to leave it now as other things to do.

I had all this after I replaced the chassis on mine and it was doing my head in anyway about a year after now I replaced the Def 200 for a Disco 200 and walked into a problem anyway to cut a long story short I removed the fuel filter complete with head and tucked away amongst the wiring behind the fuel filter there was a black earth wire not connected to anything immediately I thought it would fit the fuel filter head fixing bolts but no hole too small in eye connector on the earth wire so just earthed it to a bolt on the bulkhead and my fuel gauge worked again and I found I had a full tank of juice proved by trying to put some more in at the fuel station, it could just be a broken earth wire at the other end rather the tank / gauge end, hope this helps

cornish rattler said:

I had all this after I replaced the chassis on mine and it was doing my head in anyway about a year after now I replaced the Def 200 for a Disco 200 and walked into a problem anyway to cut a long story short I removed the fuel filter complete with head and tucked away amongst the wiring behind the fuel filter there was a black earth wire not connected to anything immediately I thought it would fit the fuel filter head fixing bolts but no hole too small in eye connector on the earth wire so just earthed it to a bolt on the bulkhead and my fuel gauge worked again and I found I had a full tank of juice proved by trying to put some more in at the fuel station, it could just be a broken earth wire at the other end rather the tank / gauge end, hope this helps

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Thanks but the gauge and wiring work because the old sender is innplace and working. I tried grounding the tank but it made no difference and it's just working now.

Well as often happens with Landy's it has fixed its self.So make your offering to the green badge god and carry on.

tottot said:

Well as often happens with Landy's it has fixed its self.So make your offering to the green badge god and carry on.

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No, it's working with the old sender but not the new one! The old sender was having some stability problems which is why I replaced it. However it does seem that changing the two electrical crimps might have fixed that issue now so I'll just get my money back for the faulty sender!

It's no doubt that there are some rubbish spare parts out there,glad you got it sorted.

tottot said:

It's no doubt that there are some rubbish spare parts out there,glad you got it sorted.

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It's back in it's little blue box now.....

Mines done that since fitting new tank but kept old sender. Put 20l in it and nothing. Got up next morning all fine. I've just taken to carrying a jerry can of fuel in my side locker just in case but I hope it's just the float sticking on mne.