I turn the ignition on, get power, but it does nothing when I turn the key. Starter or alternator?

if the battery is good it is NOT the alternator. the alternator charges the battery, if it won`t start with a new battery the alternator does nothing to affect the situation. check voltages at the starter motor connections for proper voltages even the wires that the ignition switch supplies power to. if you have proper voltages at the starter you can try hitting the starter while someone tries to start the car. if it starts the starter is worn internally and will have to be replaced.

Hi Santino, I'm Al the owner of Big As Auto Repair

Santino, are you saying when you turn the key to the start position it does nothing meaning its completely dead. OR are you saying when you turn the key to the start position the engine turns over but it will not start and run. If it does nothing then there could be a problem with the KEY Itself or could be the starter relay. Check at the starter relay to see if your getting power from the ignition switch when its turned to the start position. If you don't have power there it could be the ignition switch. But, if you do have power there then you need to see if your getting power from the relay to the starter. Reinstall the relay and have someone turn the key to the start position while you check for power on the small wire going to the starter. I'm stopping here until I know which problem your facing. For further assistance go to my website and answer the question I ask. Have an awesome day Santino. Auto Repair

I looked at info for your security system, it is starter motor disable. I didn't see 06 ford Taurus in my database, so I looked at 05.
Battery has a full charge and battery connections all good?
We can usually do some tests to see if starter motor will crank the engine, but, if the security is the problem, it still won't start.
You can check for applicable trouble codes? Try a different key?

There can be a starter lock-out which requires your to foot press the clutch or the brake pedal. But without lights you have a different problem.

Check your fuse block for power. There is a Master link somewhere under the hood and they usually put them close to the Positive side of the battery. The Master link is like a fuse only in wire form. You will also find a heavy wire that supplies power to the fuse block. Often the fusible link and the feed wire to the fuse block are the same wires.

Your Alternator, battery, etc. will test good all day long, but you need power in the fuse block.

Turn the Ignition to ACC and notice if the radio has power or turn the key to run and notice if the Brake lights work when you press the brakes.

If you have power there, then troubleshoot the wire to the starter relay. Most likely when you turn the ignition key(start) you will not have power going to the starter relay like you should. You can also test the coil Positive wire with the key in RUN position.
It should have power.

That's all I have for you.

have battery and charging system checked. you may have a bad starter.hope this helps.

If you have verified that the battery has 12volts, and there is power 12V at the trigger wire on the solenoid with the key turned to start, likely the solenoid is bad...I'd question this though because the solenoid comes with the starter and therefore should be new. (defective?) If there's no power there, re-check what you replaced and also ignition switch.

Check battery full charge, battery terminals are clean, cables aren't cracked, broken or corroded and alternator first.

Which your having replaced your starter with new already. If you're still getting nothing it sounds like a bad ignition switch.

They wear normally and need to be replaced. But as a helpful hint don't place excess keys or weighty trinkets on your ignition keys.

They wear on the seating of the key in the ignition and often promote failure in the ignition from bearing the dangling weight.

sound like and ignition switch has gone out or your starter selinoid relay on your starter is dead.

it seems that your battery is not charging..either you need a replacement or it is a faulty alternator which is not charging the battery.First thing I would suggest is to check if the alternator is producing power by a voltmeter.

try the solenoid, theres one on the starter, and there may be one on the firewall or on the insides of the engine walls