AF4500sEE fuel level input question

[rv7charlie]

I've got a new-to-me AF4500sEE, not yet powered up, for a new construction RV-7 with Van's standard 40-240 ohm float style fuel level senders. I have aux tanks, and want to add a transfer pump controller to auto-transfer from aux to main. I'd like to use the float sender signal to drive both the AF4500 fuel level gauges, and to drive a high impedance input to the transfer pump controller. I know Van's sender is ~40 ohms when full; ~240 ohms empty.

Since I've not yet powered the AF4500, I need to know what open-circuit voltage is on pins 20-23 of the engine sensor main cable connector. I'm guessing it's either main supply voltage (14V), or 5V, but need to know for sure to set up the controller. I also assume that voltage will be at max when the tank is empty, and minimum when the tank is full. Is that correct?

Thanks for the help,

Charlie

[Shawn McGinnis]

It will be pulled up to ~4v. So with the 40-240Ω you will see 0.1 to 1.0V

[rv7charlie]

Great! Thanks for the info; major time saver for me.