Hey Guys, After baseball today I went to start my 2000 F-150 and it would not even crank, tick or do anything...all the normal lights came on that normally do when you turn on the ignition but nothing else happens...I thought the battery may have been dead (unlikely but a thought) so I got my brother to come and boost me. After 5sec of the cables being connected it fired up like any other time...I drove it home (30 min drive). Turned it off, tried to start it again then the same thing happened. It seems I have full power to everything, everything works ok, headlights, cigarette lighter, radio, wipers...but it just would not start again even after I hooked the boosters up as before but for 5 min this time...no response whatsoever when I try to turn it over. Any Ideas?

 

Turn on the headlights. Turn the key to start. What happens to the headlights?

 

Always check the starter main wires. They corrode..

 

check/clean battery terminals and cables....

 

Thank you I will check the starter wires...the headlights did not dim or anything unusual when trying to start it before. Unfortunately (kinda) when I got home from work Monday morning I started fine. Has continued to start ok since. While it is actually starting I will check the starter connections and the battery. Thanks for the advice guys,

 

Thanks too for the owners manual PDF site. I don't have the manual that is long gone.

 

When my 97 did this it was severe corrosion where the cable connected to the starter motor. Battery/terminals were fine...

 

Been there!! Mine was just loose, corroded, battery terminals. If your battery has those little red & green felt washers under the terminals.....take em off and chuck em the trash!!! Don't use any of that spray crap either. Make sure they're clean and tight. ( a bad connection will kill yer alternator too)

 

I don't know the technical term for it, but there is a module or relay on my firewall (98) passenger side in the engine bay behind a black plastic cover that determines if the vehicle is in park before starting the truck. If it is malfunctioning it would give you the symptoms you are seeing. Unfortunately I do not know how it works, only that it is there and if it stops working you will not be able to start the truck. It is easy to identify as it has a bigger wire coming into and going out of it. Its not very big. Perhaps someone else will know the name of it.

 

That's the starter relay. It has nothing to do with determining if the vehicle is in PARK (that sensor is mounted on the transmission). However, the power to activate the starter relay goes through the transmission sensor so a malfunctioning sensor (and other things) will prevent the relay from energizing and allowing the starter motor to run.