resistive fuel sender

[Luciano]

Hi,

If possible, leave the original fuel level gauge connected to the sending unit.
(The sending unit is the potentiometer inside the tank).
Using the A/D inside the PIC, measure the voltage present on the wire
which connects the fuel level gauge to the sending unit.
(When the tank is empty you will have the the maximal voltage on this wire).
Use two resistors as voltage divider if this voltage exceeds 5V which is
the maximal voltage for the A/D inside the PIC. Protect the A/D input of
the PIC in order to limit the voltage to 5V. (If you disconnect the sender
you will have 12V through the fuel level gauge).

See attached BMP file.

Do not connect 12V or 5V directly to the sender.
If you do that, you will destroy the potentiometer and in the worst case
you will cause the explosion of the fuel tank. All the parts of the
potentiometer are in contact with the fuel.

Be careful with gasoline!

- Gasoline is toxic.
- Gasoline forms an explosive mixture with air.

Luciano