01 pathfinder wont start or do anything when turn key have already replaced starter,battery,crank postion sensor,2 relays under hood any ideals?

Did you use a volt meter to test voltage drop on starter circuit ? It's easy to get aggervated When you don't know what your doing .
Starter Voltage Drop

Is the anti-theft light lit on the instrument cluster ? Won't start how ? When you turn the key to start , what happens ? Nothing ? This would be a No crank - no start condition . Now if you turn the key to start and the starter engages and spins the engine and it doesn't start an run , this is a engine cranks no start condition ! Now which is your problem ?

There are two fuse's IGN A fuse 40amp and IGN E fuse 10amp ,both are located in the under hood fuse/relay box . Also there is starter relay located in the same under hood fuse /relay box . There also is a crank fuse 10amp in the under hood fuse box . Besides the fuse's and relay ,the ignition switch or the PNP - park neutral position switch could be bad . Testing the whole starter circuit should be done ! How to voltage drop test starter motor circuit

first make sure battery is charged if so then then check the relay in the fuse box under the hood find the relay that marked "ing" pull that relay then find a nother one to inter change with it, if car still wont start then ou will need to see if the in line fuse on the starter wire is good or blown if its good then you will need to pull the starter and replace it. hope this helps you

If the click you hear is from the starter solenoid mounted on the starter, it could either be a bad starter or poor connections between battery and starter. Raise the hood and listen closely near the starter for the click, when someone turns the key to crank. If the click is from the starter solenoid, have starter tested or replaced. If click is from a relay under the hood, then the start circuit will have to be further diagnosed.

Hello! Do you hear a click when the key is turned?...If no click is heard either the ignition key, the Crank relay, the starter, or the battery are suspect...Having lights and radio does not mean the battery is capable of running a starter motor......Put a meter on the battery...should read 12.5 volts...Turn key...Does voltage drop to 8 or 9 volts? Bad battery...If all is well with battery and connections to it...Check the starter fuse # 33 in the under hood fuse/relay box...If the fuse is good that click you should hear is from the Crank Relay in that box...If all of the above is OK connect your meter to the Purple wire that is connected to the starter motor...When the key is turned 12 volts must be on that wire...If there is the starter motor is defective...So, #1...Do you hear a click when key is turned...That would point at a bad starter or weak battery...#2...If you do not hear a click bad fuse #33, bad Crank Relay, bad ignition switch...#3...If fuse is good Bad Crank Relay or Ignition switch; Crank Relay is a low cost item ($10)...Replace Relay...Stop there and send a comment as to results...Guru...saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

Check the ignition switch, and the wiring to the starter solenoid. Get someone to turn the key to the crank (start) position and check for voltage at the starter solinoid. Check the starter relay and all fuses.

You mean wont CRANK or CRANKS but WONT RUN???? 4 cyl or V6 auto or manual trans????????? The 8th VIN digit would be most helpful as there are 4 different engines for that car. Its really cheaper to check items before you replace them. The starter should have a smaller BLACK wire that should have power on it when trying to crank the car. You say it wont crank, then check the neutral switch on the trans. Try putting it in neutral to start it. If it has a manual trans, the clutch switch on the pedal may be bad. There is a starter relay in the fuse box under the hood that powers the starter, does it click if you turn the key to start? if it does then the relay is at least trying to work, but doenst mean the contacts inside are good, If it does not click, then the neutral switch may be bad.Check the BLACK/YELLOW wire at the trans switch, if it has power on it, the switch may be bad, ground that (Black/Yellow)wire and see if it cranks. I dont know if there are any other relays in the fuse box that you can swap for the starter relay for test purposes.

Any starter clicking noises? Try moving the shifter to "N" neutral and try starting the car.
IF that is not successful, find the starter relay in the under-hood fuse box, replace the relay with an identical relay from the under-hood fuse box and see if it will start. This will then eliminate the park/neutral start switch and the starter relay.
Let me know what you find.

The crankshaft postion sensor is right above the starter on the engine block. Either it got broken during the starter replacement or the connector is unplugged, no crank sensor equals no spark.