I have a 2000 f150 supercab 5.4L and my problem is when I go to start my pickup i turn the key to on and everything lights up but then I crank it over and it just clicks and everything turns off. So I installed a push button start that bypasses the system. What could be the reason my key doesn't work? I would really like to know because i am getting sick of bending over to start my pickup.

 

Starting has little to do with ignition if you just hear the start relay clicking.
The crank circuit begins with a fuse that supplies power through the ignition switch, the transmission neutral switch called a DTR, then back to the start relay to a ground.
The start relay has heavey contacts that closes power from the battery direct to the starter motor.
Where are you connected in, to allow cranking?
That should give a hint as to what part has the issue.
If you can start the engine with your hook up, there is no igntion problem.
Good luck.

 

Okay, exactly what does your push button switch bypass?

Your symptoms are of a bad battery, battery cable, battery connection, or one of the large power cables off the battery.

 

Sounds like a bad connection to me.

 

my push button start bypasses the ignition and just turns over the starter. Previously it would start with key when cold and not hot but now not at all with the key. i have a brand new battery. could it be my ignition switch??? please shoot out suggestions

 

Well lets put it this way, instead of putting effort to understand what the problem might be, you spent effort to get around it.
This is how you ended up here.
At this moment we don't have any clue as to what the problem is because no testing was done to begin to get a direction to look in.
First thing you need to check out if it is a no crank from the ignition switch , is the circuit chain as I had explained.
Obviously the starter works ok as proven by your workaround, so you back up to the regular start chain and begin to find where it has gone open.
Or I missunderstand that the motor cranks with the ignition but does not fire. That would be quite a different direction to go in for the cause.
Assuming it is a no crank:
With help from someone operating the igntion switch and a voltmeter to see the voltage beginning at the fuse, you can see where it gets lost.
As a help to see the circuit, the Haynes Manuel for 97 to 03 F150 has electrical drawings in the last chapter. The first one is the starter circuit.
You need to begin to look and tell what you see for help otherwise our crystal ***** do not work to well and I don't like guessing. It's rarely helpfull.
Good luck.

 

ok thanks i will take a look into it. and it is a no crank. thanks for the help i will reply again if i find out something

 

A bigger / main library will have the repair manual for your truck. You may have to order it brought up from the basement or a branch. You can sneak it over to the copy machine and make copies. Is your work around starter setup triggering the starter solenoid or just using a switch to run the starter? A volt ohm meter can be your best friend. Your can check voltages on many things. Add a vacuum pump/ tester / gage you can almost diagnose any problem. The single model repair manual for your truck is one of the best things you can buy. Try to diagnose problems. Throwing parts at it, will just upset you when it does not do the trick!