Author Topic: How does a fuel sender work  (Read 1812 times)


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How does a fuel sender work
« on: July 20, 2015, 02:08:43 PM »
The fuel sender on my car was getting intermittent, so I needed to change it. Sadly, the sender comes as a unit with the fuel pump, so it was a case of replace the lot.

So, here is the failing sender, a thick film resistive network with a wiper to select one of 60 odd resistorsegments. You can see the tapped resistor film, with the stepped film segments, and the trim per section with the film blocks outside the main resistor arc. Wiper runs on the nickel segments and the central bar, reading around 50R when empty, and around 260R when the tank is full. Resolution is around 1l per division, you can get a reading of the fuel quantity in litres when interrogating the instrument cluster, though the gauge is very heavily damped in software, so as to not surge with motion.

Just note the brown colour is from the fuel, the original nylon plastic is actually white.

Mr Eastwood

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Re: How does a fuel sender work
« Reply #1 on: July 22, 2015, 08:13:15 AM »
pretty interesting arrangement!
Hey! Frisbee! Far out!