Rover Sports Register Forum

Does anyone know the resistance value of the fuel sender on the P2?​

I measured the value for full, it is between 50 and 60 Ohm, for empty it should be considerably higher.

I want to measure the capacity to dampen the fuel gauge. The pointer oscillates a lot when the tank is empty.

My tank is full and the indicator is at maximum. Here the highest current flows at around 50-60 ohms, approx. 200 mA (at 12 V).
When the tank is empty, the pointer goes back towards zero. Then the current must decrease and the resistance must increase. This is Ohm's law.
So the resistance of the tank sensor must be greater at the bottom (empty) than at the top (full). I am looking for this value for the bottom...

Thomas,

Sounds like your tank sender and moving coil gauge are electrically sound. The fluctuation of the reading at or near empty, I assume, is when you are driving and you don’t say it does this at, say, half or full? As such, it sounds like your issue is mechanical within the tank when the float arm is sitting low and perhaps more sensitive to road bumps etc. Personally, I’d be looking at replacing the sender unit if I was worried about an inaccurate reading. Although an easier solution is to carry a spare can of petrol, which I do anyway in case E5 isn’t readily available. However, regarding a replacement and looking on-line, I see that Holden.co.uk carry a range of tank senders of the type similar to the one in your Rover.

Tony.