Can someone explain how the fuel gauge in my little Ford Laser works.
It stopped working the other day, the fuse is OK but I want to measure 
some voltages etc near the sender unit and in the wiring loom but need a 
little advise what voltages should read etc. Are there any easy tests I 
can do to help locate the problem. Thanks for any help. Cheers

"CeeTee"  wrote in message 
news:XXqze.14222$U4.1646619@news.xtra.co.nz...

> Can someone explain how the fuel gauge in my little Ford Laser works.
> It stopped working the other day, the fuse is OK but I want to measure 
> some voltages etc near the sender unit and in the wiring loom but need a 
> little advise what voltages should read etc. Are there any easy tests I 
> can do to help locate the problem. Thanks for any help. Cheers


locate the tank sender unit, earthing the lead to it should make the gauge 
read full (ign on), if it doesn't there is a wiring or gauge fault, if it 
does then there is either a bad connection at the sender or a broken sender 
unit.  the sender unit generally has an earth wire and a sender wire, some 
also have a low fuel light and some have a fuel pump built in too, so you 
need to know what you are doing or have a good wiring diagram.

mrcheerful

Thanks for that, I think there is a plastic moulded plug that goes onto 
the sender unit. It has 2 wires/terminals and there is also an earth 
wire that goes under a self tapping screw.
I will try the earthing idea and work from there.
Thanks again.

mrcheerful . wrote:


> "CeeTee"  wrote in message 
> news:XXqze.14222$U4.1646619@news.xtra.co.nz...
> 
>>Can someone explain how the fuel gauge in my little Ford Laser works.
>>It stopped working the other day, the fuse is OK but I want to measure 
>>some voltages etc near the sender unit and in the wiring loom but need a 
>>little advise what voltages should read etc. Are there any easy tests I 
>>can do to help locate the problem. Thanks for any help. Cheers
> 
> 
> locate the tank sender unit, earthing the lead to it should make the gauge 
> read full (ign on), if it doesn't there is a wiring or gauge fault, if it 
> does then there is either a bad connection at the sender or a broken sender 
> unit.  the sender unit generally has an earth wire and a sender wire, some 
> also have a low fuel light and some have a fuel pump built in too, so you 
> need to know what you are doing or have a good wiring diagram.
> 
> mrcheerful 
> 
> 

Hi again, Carried out the tests and found a broken wire in the multiwire 
connecting plug near the fuse box. The broken wire was the power wire to 
the sender unit. I have repaired the break and all is well.
Thanks for your help.
Cheers
Chris

CeeTee wrote:

> Thanks for that, I think there is a plastic moulded plug that goes onto 
> the sender unit. It has 2 wires/terminals and there is also an earth 
> wire that goes under a self tapping screw.
> I will try the earthing idea and work from there.
> Thanks again.
> 
> mrcheerful . wrote:
> 
>> "CeeTee"  wrote in message 
>> news:XXqze.14222$U4.1646619@news.xtra.co.nz...
>>
>>> Can someone explain how the fuel gauge in my little Ford Laser works.
>>> It stopped working the other day, the fuse is OK but I want to 
>>> measure some voltages etc near the sender unit and in the wiring loom 
>>> but need a little advise what voltages should read etc. Are there any 
>>> easy tests I can do to help locate the problem. Thanks for any help. 
>>> Cheers
>>
>>
>>
>> locate the tank sender unit, earthing the lead to it should make the 
>> gauge read full (ign on), if it doesn't there is a wiring or gauge 
>> fault, if it does then there is either a bad connection at the sender 
>> or a broken sender unit.  the sender unit generally has an earth wire 
>> and a sender wire, some also have a low fuel light and some have a 
>> fuel pump built in too, so you need to know what you are doing or have 
>> a good wiring diagram.
>>
>> mrcheerful
>>