My 2000 F150 5.4L won't crank. When I turn the key to crank position the headlights stay on full bright, the instrument cluster goes blank and nothing else happens. Battery is strong and I cleaned the terminals. What are the possible causes and how do I test each?
Take a look at the wiring picture above --- follow along with me --- when you turn the ignition switch to the crank position, power is sent to fuse 21. Then if the auto trans is in neutral or park, power is allowed to flow past the neutral safety switch mounted on the transmission. Then power goes to the starter relay mounted on the right side of the engine compartment on the fire wall---the starter relay is bolted to the fire wall and uses this as a ground so when power is sent to it, it will energize and click the relay on. This allows power from the battery to be sent to the starter and the engine cranks over ---
So the best place to start on this is the starter relay --- if we start here its a good place to tell which half of the circuit has the problem. Open the hood and on the right side of the engine compartment, on the fire wall is the start relay. There may be a big black cover over it. Remove it
The relay has three posts on it --two big and one small. The small one is the one we have to test with a test lamp or a volt meter. It should be a TAN / RED wire ----have someone hold the key in the crank position and remove this wire off the starter relay and test it with a volt meter or test lamp. You should have power there.
If you do have power there, then everything from there back to the ignition switch is ok and you may have a bad starter relay or starter.
If you do not have power there, then we have to test the circuit going back to the ignition switch.
If you do not have a volt meter or a test lamp to check this out, then you can get a cheap test lamp at Walmart for $5 or you can do a simple test with a screw driver and jump the starter relay with it. One of the big posts on the relay has power all the time. Use the screw driver to jump the small post to one of the big posts, try both big posts. If the engine cranks over when you do this, then we know that the starter is ok.
Tell me what you find and we will go from there. We can go back and forth on this page.
Since I am working alone, I chose to jump the small post and large hot post (lower one) at the relay as you suggested instead of using my voltage meter. With the key in the run position (I assumed this might be necessary). I got the relay to click, but nothing from the solenoid or starter. What next? Your instructions are very clear - I appreciate that.
Very good, now we are down to a bad starter relay, starter or bad connections to battery or battery.
If you heard the relay click, this does not mean the starter relay is good. The real test is to jump both BIG posts on the starter relay with a screw driver. There will be some sparks, but if the engine cranks over, then the relay is bad.
If you jump both big posts on the relay and it still does not crank over, then jump the two big posts on the starter relay again and look at either your dome lamp or if you have a hood lamp look at one of those, and if they are on and you jump both big posts and they go all the way out; then we have a battery problem or the connections to the battery are bad.
If the dome lamp or hood lamp just dims when you jump both big posts, then this means the battery and its connections are good and you have a bad starter.
Tell me what you find
I jumped the two large posts and got sparks but no starter or solenoid response. The dome light did NOT diminish. So this suggests a battery or cable connection problem. I don't suspect the battery because it reads 12.5 v with a meter at the battery and it has been strong cranking in this very cold weather prior to the problem. No lights were left on overnight. Do I crawl under the truck to clean and tighten the hot lead to the starter, or....what?
If the lights did not go out all the way, this means that you probably have a bad starter and the battery and its connections are good. You could crawl under the truck and make sure all the connections to the starter are good before you go out and get a new starter.
Good enough. I'll sign off for now. May I follow up with you tomorrow if need be? If so do I continue with this thread in some way?Your help is much appreciated.Again, thanks much.
This question should stay up here for days. So if you need more information, we can just continue on this page.
Good luck and thanks.
Hi,I got it started using a temporary "back woods" method. Swat a hammer at the starter to release the brushes. That's what I picked up from an auto parts store and a comment at an internet forum. Didn't believe it till now. Tomorrow I will get a new starter. You've helped a lot.
Thanks. I am glad you got it.