The F3 is a simple chip for EEC-based Ford ECUs allowing the stock program to be replaced with a tune of your choice.
To install, simply clean with contacts of the EEC connector with carb cleaner and a wirebrush, and slide the module on.
It is critical that the vehicle is fully off before installing or removing anything on the J3 port. Failure to power-off the ECM correctly can result in frying our hardware, your ECM or both!!! If you have any doubts at all, remove the keys from the ignition 100% or disconnect the battery. WARNING WARNING WARNING!
Tunes can be loaded through the Burn1 via the F2A, or directly via the Jaybird.
The F3 can optionally store two programs and switch between them. You can even switch between them while the vehicle is running. The F3 adapter has a switch pin. If you connect this switch pin to chassis ground, the program will switch too. In order to program the second program you must ground the switcher line while programming!!! There is a ground pad provided next to the switcher pad for your convenience – a paperclip works wonders for programming. (FYI – Dave often uses this for nitrous – regular NA program in one half of F3, program with a couple degrees of timing and/or more fuel in the other slot, wire the program switch wire to the nitrous solenoid – see diagram)
Take a look at this picture to get an idea of what you need to do:
One thing to be careful of when you are wiring your F3 for switching: NEVER NEVER NEVER connect your switch wire to 12V!!! You will instantly fry the F3 if it sees more than about ~5volts.
The safe way to “flip” your F3 on an external signal (like nitrous) is to switch the GROUND side of your solenoid (i.e. wire to constant 12v, give the system a ground to trigger) and wire the F3’s switcher to your switched ground.
If this is not an option and you want to have a 12volt signal trigger your F3 to “flip,” you need to add a simple relay or reed switch as in the following diagram: