Fuel gauge wiring

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convertibled
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Fuel gauge wiring

Post by convertibled »

I fitted a new wiring harness when I rebuilt my 1964 convertible in 2015 so it may not be as original but I did get everything working at the time. The fuel gauge is the Gold type and has worked perfectly but the needle did move about slightly as the fuel slopped around.

Recently the oil pressure warning light and fuel gauge stopped working.

The fuse is ok
There is no power with ignition on to the green feed to the fuel gauge which is also linked to the oil warning light.
All other electrics work ok.
Im assuming there must be a break in the green feed from the fuse board in the harness so I tried a green live from the heater motor with the connector being close by.
The gauge and the warning light work but the gauge now reads about half when the tank is full and about an eighth when empty.
I put my digital volt meter across the gauge terminals and it read 12.3v when empty and 7.3 v full.

Any suggestions please?
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geoberni
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Re: Fuel gauge wiring

Post by geoberni »

Hi
I'm not sure if your car is fitted with the Voltage Stabiliser for the fuel gauge.

I'm guessing not, since you mention it bouncing around. :-?

But as a '64, I thought it should have.... :-? Perhaps the introduction of the Stabiliser was later than I thought.

You say
There is no power with ignition on to the green feed to the fuel gauge which is also linked to the oil warning light.
All other electrics work ok.
But your description doesn't tie in with either Wiring Diagram.

With no Voltage Stabiliser the connection from the fuel gauge should also branch off to the Heater and the Wipers.

With the Stabiliser, the Stabiliser feeds the Fuel Gauge and the input to the Stabiliser branches off to the Oil Pressure Light (Blocked Filter Light too if fitted) the Heater and Wipers.

Reading 12.3v at the gauge when empty is just an indication that the the Sender is at minimal resistance when Empty, therefore the gauge is the only resistor on the circuit. Whether that is correct I couldn't say.

Hopefully you have a Workshop manual and can check your wiring against the relevant diagram.

Perhaps start by seeing where the errant connections are?
Basil the 1955 series II

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ManyMinors
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Re: Fuel gauge wiring

Post by ManyMinors »

The stabiliser was fitted along with the introduction of the black speedo and fuel gauge, towards the end of 1964.
Therefore, if the OP has the earlier gold fuel gauge and it was previously working well, I'd assume no stabiliser. :wink: .
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