Fuel level pull up resistor.
Posted: Wed Dec 21, 2016 9:10 am
Hello all,
Iv been having some problems with getting my RT Dash 2 Pro to correctly read my fuel level sensor in my '94 MX5.
At empty it reads 3ohm and full is 110ohm (according to the book) Iv wired it up with a 100ohm pull up resistor but when i attach a multimeter I read 5V at the 5V source and 5V at the analogue input and 60ohms from the sensor (tank must be ~half full). Now I dont 100% understand how/what a pull up resistor does, should the difference between the two points be very small ie millivolts, or am I on the wrong track? Also do i need a slightly larger resistor so the dash can correctly read the fuel level?
In the attached image, the little boxes with the lines are multimeters.
Thanks all and Merry Christmas!!
Iv been having some problems with getting my RT Dash 2 Pro to correctly read my fuel level sensor in my '94 MX5.
At empty it reads 3ohm and full is 110ohm (according to the book) Iv wired it up with a 100ohm pull up resistor but when i attach a multimeter I read 5V at the 5V source and 5V at the analogue input and 60ohms from the sensor (tank must be ~half full). Now I dont 100% understand how/what a pull up resistor does, should the difference between the two points be very small ie millivolts, or am I on the wrong track? Also do i need a slightly larger resistor so the dash can correctly read the fuel level?
In the attached image, the little boxes with the lines are multimeters.
Thanks all and Merry Christmas!!