If it is making a 'click-click-click' noise really fast when you turn it over, that means that either the solenoid, or the electronic ignition module is busted. Easy and cheap to fix.
If it is not making the click noise, check your battery connection thoroughly. You may need to pour some coke on your battery connections to remove crud.
If you get a jump, and your car starts, but then will not start again, this is because you must allow the alternator enough time to charge up your car's battery. Leave it running for a good 10-15 minutes without the lights or stereo on just to make sure you can start it up again once you get it going.
I hope that helps :P
On the battery posts in the trunk.
check for loose connections
Your battery is not charging. It is either due to a faulty battery or a faulty alternator. Get it changed.
If you have a remote that locks & unlocks your antitheft system it could be as simple as resetting your remote, I had a similar experience.
Code PO412 for your Lincoln means that the engine is currently misfiring, could be due to the timing is off, poor fuel, if your running regular in there, stop!, start putting anything higher then 91 octane, so 91 and up, but i wouldn't go past 93, that's what i run in my 01 continental.
It isprobably not getting fuel or not getting spark.
Most starting problems are checked by starting with ethier fuel, spark, or battery.
there is a security chip under the colum maybe it fell out happened to me once
First place to start obviously battery-check voltage. Even if you have "some" power it takes almost 10 volts to turn your starter
check air, fuel, and elect.
turn the key the motor turns over but will not start
jump leads on battery pack
the battery on the Lincoln ls is in the trunk jumpstart instructions are on the trunklid
I had the same problem and found out it was the crank shaft sensor!
my 98 Lincoln had the same problem and i replaced the battery the car turns over fine now. good luck
== == Having the battery disconnected will affect the on board computer, and you should also check the starter circuit, for a problem that MAY have drained the battery in th first place. You need a professional mechanic.
A faulty fuel relay can cause a 1999 Lincoln continental to stall. If the relay is not properly reading the fuel it will turn the car off.