I replaced the battery on my 03 Expedition. Drove it 75 ft and it just died- no crank no start. I have done every test I can think of. It's not the battery, the starter, all fuses and relays are good, doesnt seem to be the neutral start switch. All the lights, windows, doors and radio work. The blinking anti theft light (pats light) on the dash board is NOT blinking though. When I hit the ignition, the only thing I hear is a click from the relay and I can not hear a fuel pump running. The emergency fuel shut off is ok. I am out of ideas! When I hook up the code reader all I get is "data link error" It won't read the codes. Any suggestions are appreciated

 

Data link error may mean the fuse for the obd2 port is blown. Have you checked for fuel pressure when its a no start? Does the engine turn over at all when you go to start the vehicle? Do you have more then one key to try?

 

I cant check the fuel pressure bc it wont start at all. When I turn the key, the lights, windows and radio work. I have tried both keys and all the troubleshooting to see if the anit theft system locked it up. Where is the obd2 fuse at? Thanks for the help!

 

You can verify fuel pressure if the engine will not start.
When you turn the key on the fuel pump is activated for 2-3 seconds and will provide a reading even if the engine is not started. You can even turn the key off wait 2 seconds and turn it on again to see if the reading changes. One of the quick checks is to listen for the fuel pump run for the 2 seconds. If you do hear it run , then you know it is getting some power, if not, then you need to determine why not.

Something is going on and we need to see if we can pin down just what it is.
There is some help available if you have the owner's manual. Look in the maintenance section for the fuse and relay section and it will list the fuse and what it protects and a diagram for the relays.
Not sure if this is what is happening, but it does sound like power is getting interrupted to the circuits that control ignition/fuel.
Can you verify this? Do you have any kind of test equip to perform any checks? (Test light- Multimeter) You can use a test light to check fuses.

 

There is no power to fuel pump, starter, the PATS light is NOT blinking. I am thinking the PATS system has gone bad. Could this be part of the issue I am having?

 

If there was a problem with the PATS, the light would tell you that.
When the PATS is preventing theft it will not permit a ground for the starter relay, hence no start.

The PATS will not stop a running engine as happened with your vehicle.

 

I know this one is old but any luck with fixing the problem? I got one that is almost like the one you have.