5 replies to this topic

[KevinS]

1990 998cc Mini 3 x clocks with Ballast Resistor

I'm still trying to resolve why I get odd fuel level readings and so connected a multimeter between the two male spades on the sender unit whilst fitted in tank and earth and power wires are still connected. Turned on ignition (orange and red lights lit) without starting car. The multimeter reported voltages between 0.5 - 4.8 with voltage fluctuating between these values. Then repeated with another known good sender unit and same values repeated.

Is anyone able to confirm if this is normal or should I be getting a static constant reading and if so what should the value be.

Many thanks.

Kevin

Edited by KevinS, 06 March 2022 - 03:41 PM.

[viz139]

The fuel gauge is feed from a 10 volt regulator so 0 to 5 volts would be the range depending on fuel level.

[KevinS]

Hi Viz, thanks for taking time to reply. However..... the voltage reading on the multimeter is constantly fluctuating between the values I originally posted whilst the float is in a static state. I understand resistance will change depending upon the float position but fluctuating voltage reading when static?

[mad4classics]

The original Lucas bi-metalic regular provides a nominal 10v by switching the 12v supply ON and OFF cyclicly giving an average of 10 to the gauge. What you're seeing is this fluctuation the upper level of which will be dependant on the level of fuel if the sender is still connected.

Edited by mad4classics, 06 March 2022 - 08:51 PM.

[Spider]

With the Sender connected, the voltage across the sender will depend on how much fuel is in the car.

With the Sender disconnected, there should be 10 volts on the Green / Black wire to Earth (with the key on), but you won't measure that with a digital meter (unless the stabaliser has been changed for an Electronic type).

There's some info here that might help;-

https://www.theminif...hs-fuel-gauges/

 

[KevinS]

Thanks to all. Also found this article on the forum. Interesting read.

https://www.theminif...r/#entry3576145