Starter has power to it but has some problem from the key to the starter Does this model have a relay or something?

Hey! If your 2002 Nissan Xterra attempted to start without the keys in the ignition after replacing the starter, there may be an issue with the electrical system or the starter installation. Here are a few things you can check:

1. Wiring connections: Double-check the wiring connections on the starter. Ensure that the positive and negative cables are securely attached to the appropriate terminals on the starter. Make sure there are no loose or exposed wires.
2. Starter solenoid: The starter solenoid is responsible for engaging the starter motor when the ignition key is turned. It's possible that the solenoid is malfunctioning or wired incorrectly. Check the solenoid connections and wiring to ensure they are properly connected and in the correct configuration.
3. Ignition switch: It's unusual for a vehicle to attempt to start without the keys in the ignition. There could be an issue with the ignition switch or the wiring related to the ignition system. Inspect the ignition switch and its wiring for any signs of damage or loose connections.
4. Security system: Some vehicles have a security system that can prevent unauthorized starting. If your Xterra is equipped with a security system, ensure that it is not causing the issue. Refer to the vehicle's manual or contact a Nissan dealership for instructions on troubleshooting the security system.
5. Starter replacement: If all the wiring connections and components appear to be in order, it's possible that the replacement starter is faulty or incompatible with your vehicle. Consider double-checking the specifications of the new starter to ensure it is the correct model for your Xterra.

If you are unsure or uncomfortable with performing these checks yourself, it is recommended to consult a professional mechanic or contact a Nissan dealership for assistance. They will have the expertise and tools necessary to diagnose and resolve the issue with your Xterra's starting system.

Two possible issues.
Starter relay (what puts power to your starter when you turn the key) or
Your starter is bad.
I would start with the starter relay because it is cheap and easy to replace.
The whirring sound could be your fuel pump or the starter turning but not connecting to the engine to turn it over. Depends on how loud the whirring is...

Good luck.
Semper Fi,
Z

Bad ignition switch. I have seen lots of these go bad. Also check starter relay. What happened was for some reason the starter relay was activated and sent a signal to the starter to start the car even though the car was running

If the battery is good, then there should be power at the starter solenoid. The solenoid is connected to the starter.The solenoid is energized by the ignition key. When the key is turned, the starter solenoid allows power to feed the starter. Try tapping the starter solenoid while turning the key. Have a friend help and use something non metallic to tap the solenoid. Good luck!

There is probably a starter relay in the under hood fuse / relay box. When you turn the key to start on newer vehicles that power signal isn't going to the solenoid . It's an input to a control module . BCM , PCM etc... Then the PCM energizes the relay closing the contacts sending voltage to the starter . What year , make an model vehicle ? Do you know what a relay is ?

At the starter relay, you have two red or purple wires, one goes to the starter and the other comes from a 30amp fuseable link. Is that fuseable link circuit hot ?
From the key switch, power goes thru the alarm relay, then the clutch safety switch or automatic selector switch, then to the starter relay. The fourth wire on the starter relay is a ground.
You should be able to put power to the starter relay on the white or yellow wire coming from the safety switch to make the relay engage.
My guess is something wrong with the alarm system.

The most common cause of a non-starting car is the battery. It is either weak, (low voltage) dead, (zero voltage) or has bad connections. (corroded or loose) I will assume you have a fully charged battery with good connections. (both to battery and starter relay)
If you remove the starter switch lead (small wire) from the starter relay and apply +12v from the battery to its respective prong or lead on the relay, and your starter cranks, your starter switch is faulty. (not to be confused with your key switch). If you jump the two large wires together on the relay and it cranks, then the relay is faulty. If you jump the two large wires together and nothing happens, then starter is faulty, or wires to starter are loose or broken. Picture of starter switch prong on the relay is pictured. NOTE: sparks are to be expected, so don't be too scared. Pictured is a starter relay that is seperate of the starter, on models with starter and relay mounted together, its very similar.

The ASD relay powers the injectors and the coil.
Have you checked it to see if you have power in and out ?
The engine computer grounds the starter relay, injectors and coil, could be something going on with it.

Find the starter relay under the hood. It may be bad and stuck so power continues going to the starter. Try a new relay Or try pulling off the small signal wire on the relay (it is from the switch), and hook battery up. If starter continues to run, the relay is bad. If starter is stopped, put the signal wire back on relay. If starter now starts operating, and key is still off, then switch may be bad .Location of relay may be at left front fender apron, in front of shock tower (like on earlier taurus models).

Have you checked (or wired around) the fuel pump relay?