fuel gauge

[ground hugger]

Hi folks
A few months ago my fuel gauge packed up ,went from full to empty over about five miles of my journey.
At first I thought id got a leak on the tank it went down that quick. Pulled over and Checked for leaks..no fuel smell, so carried on until I found a petrol station.....put £7.00 in and it was full :?
I thought then it would be the sender, this was brand new last year.
Yesterday I had a look ,removed the lead from the sender and earthed it out . Fuel gauge shot up to full, removed sender from tank and dismantled it thinking the wire had snapped or come unhooked from the float.
Everything was fine and id got 3/4 of a tank of fuel
Do you think it could be the gauge ?????

I also noticed when I turn the ignition on the gauge moves up a few mm's just short of the empty line. Also when I flash the high beam the gauge moves up/down a few mm's. Is this normal behaviour when the lights are flashed (engine not running):? .....Dave

 

[rickyrooo1]

if you've earthed out the sender on the tank and the gauge went up it's going to be your sender that's broken

 

[ground hugger]

if you've earthed out the sender on the tank and the gauge went up it's going to be your sender that's broken

Ive just removed the sender (after looking on utube how to check a fuel sender) and put a multimeter on ohms and got a reading between 02.4 - 02.7 in the empty position and a reading between 80.0 - 80.7 in the full tank position, from this I presume the sender is working :? .....

 

[subheatadey]

You presume correctly

 

[ground hugger]

Thanks for conferming ,I'll try and test the gauge tomorrow cheers...Dave

 

[bluenose]

if guage and sender are working could it be connection between the sender and earth is problem?

make sure you post back your solution as mine is on the to do list also

 

[ground hugger]

Will do and I'll check the wires strange how it doesn't work though and the gauge reads full when it's ground out :? ....Dave

 

[ground hugger]

Looks like the gauge is dead
Ignition Off



Ignition On



Ignition On and sender earthed out


Put another earth on the sender but didn't alter anything.
I got a reading of 3.8v at the sender and 3.8v at the gauge on the brown wire. On the black wire feeding the fuel gauge I got 13v with the engine running....

 

[bluenose]

how can the guage be dead if it goes to full when you earth it?

 

[ground hugger]

how can the guage be dead if it goes to full when you earth it?

To be honest I don't know, I'm just surmising it is because it doesn't do much :lol: .
Electrics aren't my thing really,there's 3/4 a tank of fuel and when the ignition is turned on the gauge does move but only just.
If I remove the sender and tilt it the ohms reading changes,I haven't checked the voltage to see if this alters.If by tilting the sender and the volts change but the gauge doesn't move,would this suggest it's no good ?

 

[ground hugger]

how can the guage be dead if it goes to full when you earth it?

To be honest I don't know, I'm just surmising it is because it doesn't do much :lol: .
Electrics aren't my thing really,there's 3/4 a tank of fuel and when the ignition is turned on the gauge does move but only just.
If I remove the sender and tilt it the ohms reading changes,I haven't checked the voltage to see if this alters.If by tilting the sender and the volts change but the gauge doesn't move,would this suggest it's no good ?

The gauge that is.....

 

[bluenose]

have a read of this

http://www.nls.net/mp/volks/htm/fuel_ga.htm

It says at the bottom if when you disconnect cable from the sender your gauge reads nothing and if when earthed to chassis it goes to full the guage is okay and problem is with sender. So I guess your gauge is ok

I think you need to check ohms reading through the sender when float is up and down

 

[ground hugger]

have a read of this

http://www.nls.net/mp/volks/htm/fuel_ga.htm

I think you need to check ohms reading through the sender when float is up and down

Checked the ohms and the sender appears to work got a reading of 02.4 - 80.7 ohms
I've just removed the sender again to check the volts, I've extended the wires to the sender and with the ignition on tilted the sender and the bugger worked on the gauge.
Checked the volts and got a reading of 0.02v full and 3.2v empty, So I put the sender back in the tank and nothing again.
Removed the sender put it in a sink full of water and it works (checked by ohms readings),So I put it back in the tank and guess what it doesn't work.......The ohms reading is 32.0 this says its floating in the tank but the voltage is 3.2v so suggests its empty.....AAAAAARRRRGGGGHHHHHHH.....

 

[ground hugger]

Just popped out and 10 minutes into the drive and the gauge pops up to half full :shock: :?

 

[bluenose]

so sender and guage both work then lol

where did you stick that extra earth to the sender? I'm thinking when I do mine i'll stick it from one of the bolts on the sender to a good earth in the engine bay.

 

[ground hugger]

Looks like there both working ok now,still unsure about the reading though on the gauge .
Its showing just under half a tank but there's more like 3/4 a tank.The original earth is fixed to the sender bolt but goes towards the firewall but I can't see the end of it .
I've got a cut out so I can get to the sender easily (good job I have) :lol: So I've ran another earth off the sender bolt and earthed it to the metal above the tank where I can see its clean....Dave