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Fuel gauge

Posted: Mon Sep 29, 2014 1:13 pm
by Unimatrix1066
Hello
I ve just bought a 2 door morris 1964 , the fuel gauge always reads full when the ignition is on and nothing when off.
I ve disconnected the sender to see if that makes a difference but does not.
The previous owner converted the car to an alternator and negative earth so do not know if this is an issue.
The ignition light also gleemers when the lights are turned on

Re: Fuel gauge

Posted: Mon Sep 29, 2014 1:21 pm
by Unimatrix1066
Forgot to say the sender has been replaced as old one in boot with dynamo as I take it by other posts there are different.

Re: Fuel gauge

Posted: Mon Sep 29, 2014 5:13 pm
by panky
It shouldn't make any difference to the gauge converting to negative earth, I did it and it operates as it did previously - it sounds as if the wire to the sender is going to earth somewhere that's assuming the gauge isn't faulty. As for the ignition light first check that the fan belt is tight, it could be slipping under the extra load on the alternator. If that's OK check the output of the alternator with a multi-meter.

Re: Fuel gauge

Posted: Mon Sep 29, 2014 6:26 pm
by mike.perry
The glimmering light could be a loose ignition light holder allowing the reflection of the light from the panel lights.

Re: Fuel gauge

Posted: Mon Sep 29, 2014 8:23 pm
by Unimatrix1066
The ignition light is defiantly glowing slightly, I will check the wiring from the sender to the gauge hopefully it's not the gauge
Cheers

Re: Fuel gauge

Posted: Tue Sep 30, 2014 6:53 am
by bmcecosse
It's not the gauge - it moves ! Pull the wire off at the gauge and then check it with a meter. To check for external light on the Ign warning - switch off the panel lights - does it still glimmer?

Re: Fuel gauge

Posted: Tue Sep 30, 2014 12:04 pm
by alexmcguffie
With the ignition on, disconnect the wire from the sender in the boot and see if the level falls to empty. If it does then your sender is at fault. If not then you have a short to earth between the guage and the sender.

Re: Fuel gauge

Posted: Mon Oct 13, 2014 9:08 am
by Unimatrix1066
I managed to look at the fuel gauge this weekend and found that guage registers full when screwed back into the speedo and earthing out to the chassic.
I ve noticed there is no voltage regulator also on the back off the speedo where these fitted across the range?
The gauge I had to take apart as when I undone one of the terminals the terminal came away from the body.
Inside are 2 coils which area attached to the housing via the 2 nuts on the rear of the body .
There is also a wire resistor between the 2 terminals which has got very hot as it's black rather than a copper colour

Re: Fuel gauge

Posted: Mon Oct 13, 2014 9:50 am
by bmcecosse
The later cars with 1098 engines have voltage regulator (to 10 volts) on the back of the speedo - and the 'hotwire' gauge (usually black - I'm not aware they were ever silver or bronze... but no doubt someone will correct me !) which slowly rises to the correct reading when you switch on.

Re: Fuel gauge

Posted: Fri May 01, 2015 8:54 am
by Unimatrix1066
I ve managed to a look at the whole setup , an open cct gives a full deflection on the gauge and as resistance is increase it drops the needle I found an open cct on the wiring between the sender and speedo plus the previous owner has replaced the sender which works the wrong way round.
A box of bits with car had the old sender for refitted and working ok