This document discusses how to modify an AF-3000 or AF-4000 series EFIS set up for older VDO or Stewart Warner oil and fuel pressure sensors to read the currently sold Kavlico pressure sensors instead. Also applies to switching fuel tank sensors from reading resistive tank floats to capacitive tank systems.
Resistance to Voltage Field Modifications
THE DOCUMENT WILL EXPLAIN FUEL TANK FLOAT TO CAPACITANCE AND
FUEL/OIL/TEMP RESISTIVE TO VOLTAGE MODIFICATIONS.
ONLY MODIFY THE JUMPERS THAT YOU ARE WANTING TO CHANGE.
Remove a total of 14 screws that hold the rear cover;
4 from the left and right side and 3 screws on the bottom and top.
Remove DSUB jack screws.
If your unit contains air data you will need to remove two screws on both sides of the pitot/static block
Slide rear cover off.
If your Engine Board looks like the picture above:
Clip the jumper loop on the inputs that require 0-5 volt sensors.
If your Engine Board looks like the picture above:
Use an craft knife to remove the jumper between the two pads on the inputs that require 0-5 volt sensors.
Verify with a multimeter that the two pads have been seperated with a reading above 5 kΩ.
A reading less than 10 Ω indicates a connected jumper.
Install rear cover in reverse order. Use blue loctite or thread locker on screws.