Whilst tanking the sender out of an S3 fuel tank today, I discovered something interesting…
The thing in this picture next to the float arm is a low fuel level sensor.
(http://i589.photobucket.com/albums/ss333/gsxrmovistar1/DSCF1408.jpg)
The revised dash models which were only available in the US in left hand drive had a low fuel level light but all UK spec cars across all 3 series didn’t have this feature. I’ve often thought this was strange given the cars appetite for fuel and the rest of the car being so well equipped for its day.
The fuel sender unit has 3 male terminals on it in a plastic housing and the plug from the car loom is also a 3 way but has only 2 wires going into it. The 3rd space in the plug is left empty.
(http://i589.photobucket.com/albums/ss333/gsxrmovistar1/DSCF1409.jpg)
I got an old piece of loom with a female plastic plug on it, cut the plug open and retrieved the female terminal connector…. This then just pushed into and locked in place in the spare space in the terminal block on the sender wire.
(http://i589.photobucket.com/albums/ss333/gsxrmovistar1/DSCF1411.jpg)
My guess is that if the fuel level drops, to say 1 gallon left, the sensor will go to ground and complete a circuit so if I connect a bulb or led to +12v that comes live with the ignition and the other end to this sensor, I should have a working low fuel light.
My thoughts are that when the new tank was introduced for the Series 3,( and the stateside GSL-SE) Mazda just used the US spec sender and ignored the fuel level sensor part of it as the UK cars weren’t wired for it, as they still used the old dash.
Where to site the warning light is my next puzzle. Ideally, a led in the instrument panel would be best but I can’t really be bothered to take the clocks out….
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I bet there is a spare space along the row of warning lights on a stock dash...
I reckon the one to use would be the pointless one on the far right that illuminates when the headlights raise.... what\'s the idea of that ...?
thing is, I was planning to change that one to an overboost warning light by wiring it to the 8psi pressure switch and changing the light symbol to say \'overboost\'.
I suppose if I do drop the clocks to do that, I could put an led into the fuel gauge at the same time.
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Haha yeah I\'ve always wondered why they bothered with that light but yeah an overboost light is probably of more importance and like you said if you\'ve got the clocks out anyway you just aswell drill an LED into the dash.
my tank is always empty no need for a light! lol