Hey guys,

My 1999 F150 (5.4L) won't start. I drove it to town yesterday (about 20 miles) and went inside Home Depot. I came out about 30 later and it wouldn't turn over at all. There was just a click under the dash and the lights would temporarily go out until I released the key. I tried to jump start it but, it wouldn't start. I took the battery out and had it tested at AutoZone. They said the battery was fine.

I left the truck overnight and went back this morning and it cranked right up. I drove it back home and turned it off and now it won't start again. So, I got out my Hayne's manual and started testing.

I connected a jumper from the positive post on the battery to the exposed lug on the starter relay on the fire wall and it started fine.

I don't have a test meter here to check ignition and transmission sensor.

Any Ideas?

Thanks for any help.

Mitch

 

Get a meter so you can do diagnoses, else it is just guess work.

 

I called a friend of my daughter, who's a mechanic, and he gave me some advice. We put a "test light" between the ignition wire (small wire) and the starter relay. (the one on the fire wall)

When I turned the key the light lit up. So he said the Ignition was probably fine. He said that it was most likely the relay getting hot and malfunctioning. I picked one up at Advance for $22 and put it on in about 10 minutes. It cranked fine after I put the relay on, so I'm hoping that was the problem. I let you know if not.

Thanks