Fuel Gauge Problems

So I got in the truck yesterday morning and the fuel gauge reads lower then empty, off the scale low. I checked the connections to the fuel sender thing on the tank and they are all nice and clean. Went through and followed the wiring, as far as I could and didnt see anything bad to an untrained eye. Then checked my fuses and the top row, 4th one down (starting on the left) had blown, it was 25 one. Looking at the little schedule on the fuse cover it is supossed to be 15, is that right??? So I replaced it with a 15, and it blew again, then put another 25 in it and it blew again. Does this mean that maybe there is a problem with the wires???

I was looking through on here and read to "Earth" the actual gauge to see if the gauge is broken. I tried it myself along with messing around with the instrument pannel and ended up blowing all my fuses for the turning signals and the rest of the instrument lights. So I dont understand how to go about "earthing" the gauge. Could someone give a idiots guide to this for me so I dont mess anything else up.

Also, if you may know how to check if the fuel sender thing in the tank is working or not, would I have to take it out and give it a look over???

thanks in advance

Sounds like you have a short to earth

Two ideas:

1) Remove all the wiring from the fuel gauge, and test by connecting directly to the battery.

If gauge is working will read full - if gauge as a fault internally you'll have a lot of sparks and smoke - sorry!

Alternatively, check with a test probe or continuity meter

2) Look for signs of chaffed wiring from the fuel tank sender to the gauge - possible where is passes through/rubs against chassis it has become damaged allowing a short

As for testing the fuel sender - effectively it works by changing the resistance as the float inside moves - the lower the fuel the increased resistance which deops the voltage from 12v to whatever, which in turn causes the fuel needle to move lower.

Can test in situ by connecting a multimeter to the sender feed (and earthing the other probe) to see if you get a reading, but would need to remove the sender to move the float about to see if the voltage changes

Thanks very much Station house, Once I get home after work I'll try the fuel gauge first by hooking it up to the battery, hopefully no smoke starts coming out!

If that works I'll attack the fuel sender feed.

I have exactly the same problem and its really annoying!!!

yea I'm anoyed by it, lucky I filled it up the night before so I know I got a good amount of fuel in it. I wonder if during the fill up something happenend to the float in the tank...

quick thought for checking the sender, when I conect the probe to the electrical unit on top, if I give her a good shake up and down will that be enough to get the float moving up and down, thus changing the resistance??????

USLandy said:

if I give her a good shake up and down will that be enough to get the float moving up and down, thus changing the resistance??????

Click to expand...

Might do - more likely if only say 1/4 to 1/2 full than if nearly full - more ability for fuel to 'slosh' about if less fuel in tank

What are you driving? If a 90, then fuel sender under drivers seat, very easy to remove

If a 110 it's a bit more awkward as involves laying on the ground!


Personally would be surprised if filling up damaged float - floats sometimes can stick causing it to read full when it isn't, not come across one shorting out before.

Tis a 90, but my tank is under the the passenger seat due to the steering wheel being on the left hand side. I'm across the pond over in the states. We missed our old series and defenders so we got one shipped over

USLandy said:

Tis a 90, but my tank is under the the passenger seat due to the steering wheel being on the left hand side. I'm across the pond over in the states. We missed our old series and defenders so we got one shipped over

Click to expand...

:doh::doh: Makes sense

Did you have to convert it to LH drive once you got it over? Must have been a task to source all the parts if you did

We had the guys at liveridge do it for us, they have send a good amount over sea's so we thought it would be easiest to get the car done over in England rather than try it over here. They did a fantastic job on it too!

The companies in the states which do rebuilds charge crazy amounts. For example, place called "east coast rovers" do 90 and 110 rebuilds. The 110's they do start at 170 thousand!!!!! yes that is right start at 170 thousand dollars. Also they are all a bunch of no good Fu**s. But getting parts over here isnt too bad, a few companies do most of the stuff. But a lot of guys who have the 90's do mass orders where they all fill a shipping create up with goodies.

If some good old English men who are very knowledgeable about the defenders come here and start doing the rebuilds for decent money you would make a nice little company for themselves! There are always people looking for defenders, I've been offered close to double what I paid for my 90 already, only had it here for a little under a year!

Very interesting - thanks for sharing

Hope you get that gauge sorted

Sorry - another daft train of thought

What else runs through that fuse thay first blew?

My landy is at home so can't go and look at the fuse panel! There won't be one fuse just for the fuel gauge!!!

Memory (and really is so please check) is that it might also power the indicators or wipers - could of course be an earth fault with those and nothing at all to do with the fuel gauge or sender

I hope so to, I'll post on here some updates later on.

Thanks for the help Station House

I'll run out and check quick, But both my indicators and wipers were working this morning. I'll post back in a min

alright, so the fuse for the fuel gauge is the one with the indicators and the wipers like you said, but the one which is blowing on me is the one with the fan looking symbol....

forgot to mention the gauge still isnt working even though the fuse is good, so now that i checked all that i realize something else is wrong with it... :doh:

Sorry to have doubled your problems

The single fan picture fuse is the heater blower.

Could be a wiring fault, but another (not uncommon) cause of the fuse blowing is if the fan motor has seized.

They can do this either because the motor has given up, or because a build up of mud and other crap is stopping the fan from physically turning.

Ways to test in situ are multimeter, test probe or direct wiring (but again direct wiring carries risks if there is a short)

Not too bad a job to take the fan out to check - photo guide link for you:

LandyTown :: Defender heater matrix removal in Pictures

Fault could also be (but less likely in my experience) with the fan switch itself - you might want to quickly unscrew and check the connections there - a test probe for earth faults would be useful - before taking out the heater itself

whats the fan heater for exactly? If it is for heating the passenger area it doesnt do anything anyway so I'll worry about that later....

Yep

Hot water from the engine block passes through the heater matrix, so allowing warm (it never gets HOT in a Defender) to be blown into the cab either by ram air (driving along) or boosted via the fan.

If it isn't working, I'd suggest ensuring the fan is off (just in case it's pushing current through to a seized unit - small risk of an electrical fire) or better still removing that fuse completely for now.

Landys have a strange habit of electrical faults impacting other things that you wouldn't think they would or could - AndyLand has a thread (long) about how his headlamps made his windscreen wipers activate! - I'm not saying the busted heater fan and fuel gauge are related, and couldn't guess at a how, but maybe possible that somehow current from one is finding its way to the another causing the gauge to read 'full'

without reading the fred:
is "dipstick" an answer?

philvy said:

without reading the fred:
is "dipstick" an answer?

Click to expand...

Indeed it is!






To a completely different question. Well done. Want a doughnut?