Started acting funny 3 days ago, acted like battery was dead. Battery charged overnight and acted fine the next day. That evening, battery cranked once, then clickety click click 30 times till it died. I got it home and opened her up. Battery worn down. Thought it was the firewall starter relay...replaced that, hooked everything back up correctly, but not starting. Starter connections good. replaced main power lead wire (2-0 cable) from battery to starter and battery to relay. cranks and cranks and cranks with key in ignition (run position) and arcing across the starter relay (with a screwdriver like everyone mentions). It will never fire up. just cranks until it drains down the battery. And once while I was shorting the relay the power flickered and the lights flickered off and on once and since then there's no electrical in the truck. All the fuses I've tested (not relays) in the drivers side engine and the drivers side panel (up under by the parking brake release and the hood release) are intact without damage.

1. why do i have no power

2. could i have inadvertently reset the pats system and so it just cranks now not recognizing my key.

3. why the fart wont the truck fire up and run?

Any and all help appreciated. I've leared a lot from all 20 pages of posts related to this topic as I've poured over them the last 2 days but i still have no good explanation or focus on where to look for the problem as I've described it. Thanks to any help you guys might have

Dave

 

Pats will still allow it to crank, but no fuel. Check the mega fuse and any fusable links you can find. If you cranked and cranked till the battery was dead you may have fried something. Plus the fuel pump shuts down after about 5 seconds of constant cranking or by flooring the pedal while cranking. Can you hear the fuel pump run when the key is first turned on?

You may have a fuel pressure issue.

 

If it's PATS related, the THEFT light will be fast-flashing. Have you bothered to observe it?

You blew a mega fuse, burned out a cable, or damaged the battery.

 

The theft light does not illuminate. where are the mega fuses on a 2001 F 150?
Thanks

 

When the key first turns on I hear crickets only. The truck is dead. no fuel pump, no radio, nothing...

Thanks

 

Anyone know if there are such things as mega fuses on my truck? It's behaving like I've left the door open too long and the automatic light shut off happens. When I do that, the key goes in the ignition and everthing turns back on. If I've fried the ignition, how can I tell? Just replace it on the steering column? Thanks!

 

Weak battery. Charge it. It should cramk 10 starts easy. It doesnt it os shot.

 

The Mega fuse should be either on the firewall or in the junction box, both are located in the engine compartment. It looks more like a bar or a thin metal strap, not like a regular fuse IIRC.

 

thanks to you both. Turns out it was the battery. Then i got it to start and burned up the starter because it won't disengage and just burns up when the engine is running. I've rewired something incorrectly.