fuel gauge not working

[crankshaft77]

Hi all my fuel gauge is not working which is annoying I put in a new sender unit as the old one was buggered. I,ve tested the feed wire that goes to the sender and with the ignition on the light flashes red then green on my tester.if I put power to the wire with the ignition off I can see that the gauge works fine! Anyone have problems like this before?

[bmcecosse]

Looks like the connections are wrong on the gauge ? The 'sender' doesn't send - it earths.. Getting movement when putting power up the sender wire suggests the connections on the gauge may be wrong. Is it silver/gold - or black?

[crankshaft77]

The wires that go into the back of the fuel gauge are green/black and seem to earth ok when I put the tester on them and now I,ve tested the wire at the sender and its green but still the gauge won,t budge.

[bmcecosse]

Green should be the power feed - and green/black the sender earthing wire......

[crankshaft77]

That's right I took the wire off the sender and earthed it on a bit of metal and the gauge never moved.so I,m wondering could my gauge be knackered!

[bmcecosse]

You say it worked when you applied power to the sender wire....... The connections are wrong...and you still don't say - is it silver or black ?

[crankshaft77]

Yes bmc it worked when I applied power to it.As for silver or black I take it you mean the clock colour which is black..The green feed wire you mentioned is on the bottom left connector which would be behind the empty on the gauge then the black/green wire is going to to the other side of the gauge up to the regulator at the top of the dial if that makes sense to you.

[ManyMinors]

On the later cars with the black faced speedometer there is a voltage stabiliser which is linked to the fuel gauge. It is attached to the rear of the speedo. If this is faulty it will cause the fuel gauge to read incorrectly.

[bmcecosse]

The green/black indicates a wire that should be running to earth eventually .....it should run to the 'sender'. The green wire - from the 10 volt regulator (because it is a black 'hot wire' gauge) is the power feed. However - being a hot wire gauge - it should work either way round - so it's a bit of a mystery. Test it with a feed and earth with everything else disconnected - does it work?

[crankshaft77]

Tried that not budging.I put the tester on the feed wire and its turning from live to earth surely that can,t be right?

[bmcecosse]

I suspect you are somehow sending the 10 volt stabilised supply directly to the 'sender' - without going through the gauge ! You said earlier that it worked !! Did you take ALL the wires off the gauge - then put power on one terminal and earth the other one ? Use wanderr leads - none of the mixed up wires from your harness. The gauge should slowly run up to FULL.

[crankshaft77]

Sorry I put earth to one side of the gauge and power to the other side there and yes it did go up too full.but I tested the feed coming from the regulator and when I turn the ignition on it stays red for two seconds then goes between red and green there ain't many wires that I could get muddled up.could it be a possibility that the regulator is playing up?

[bmcecosse]

Possibly - just bypass it temporarily - does the gauge work? Your 'tester' sounds a bit weird (green and red ???) - use a voltmeter! At least it will 'pulse' with the stabilised supply -which simply switches on and off to give an average 10 volts..... Or use a bulb on leads - you will see it dim and brighten - maybe even flash on/off...

[crankshaft77]

When I say green and red= earth and feed)The feed going into the regulator is going from feed to earth instead of just a constant feed! And I,m getting the same from the earth to the sender also!

[bmcecosse]

Because the 10 volt stabiliser is pulsing on and off.... Get a wee voltmeter from maplins.... And try wiring the gauge direct to the sender...

[MontyTheMinor]

Crankshaft, did you get this issue sorted?

My fuel gauge is showing empty even though I have filled the tank, don't know where to start!

[bmcecosse]

Follow the suggestions in this thread......

[mike.perry]

Meanwhile carry a spare gallon can of fuel in the boot, and a dipstick

[MontyTheMinor]

Evening,

So after sorting an idling screw issue and cchecking the gauge is getting power my fuel gauge has randomly started working perfectly. Very pleased as now I can go further that around the block!