Truck cold starts ok, but battery doesn't work when starting hot
 

I’ve got an issue with my ’99 F-160 V6. I can crank it up cold and it starts right up. But if I drive it, turn it off for a few minutes it won’t crank for at least the next 30 minutes. The lights shine bright, the radio plays, the car gets power, but it just won’t start. When I try to crank it all I hear is one click from the solenoid.

The auto place tested my battery(only two months old) and said it was bad. So they replaced it but the new battery does the same thing. We’ve already changed the solenoid and I just got a new fuel pump. We also checked the fuses and they seem like they’re in working order and don’t look burnt. What could cause these problems AND give the battery a bad reading? Thanks guys!

It could be another bad battery or else the charging system (alternator) isn't working just right.

Have you had the charging system tested on the truck?

Also, do you have cruise control?

If you do, I would look and see if it had the recall harness done to it.

I don't recall the alternator being checked in the past. Would that issue still allow the battery to power the lights and all perfectly but not crank the truck? The lights don't dim or anything when I try to crank it.

But I did have the cruise control recall done several years ago. Is that the one you're talking about? I've had this truck since around 2001.

Thanks!

Sounds more like a bad engine ground strap. Next time it happens take 1 jumper cable and run it from the engine to the frame of the truck. Make sure the areas of contact are clean. A wire brush is great at this. If a ground strap is marginal it will conduct electricity when cold but as it heats up it no longer allows enough thru to do any good. Once everything cools down, everything works again.

Have you had the starter checked? It sounds like something is getting hot and expanding enough to break the flow of electricity. Measure the resistance of your + wire and your - wire cold and hot. One is breaking down enough to limit the current. The starter is the biggest draw on your truck. Everything else might still be getting enough power to still work.

Check the small wire where it connects to the bendix, they can corrode there. When you get a replacement starter some have a new wire to splice on, I think they suggest about 4-6 inches to cut it back. When the truck gets warm it may have too much resistance as others have said.

2016 F150 XLT 3.5Ecoboost FX4 45,xxx miles
 

Having the same issue. One dealership found a damaged wire in the relay harness. Repaired it and the problem stopped for about 3 months. The problem started again yesterday. Now the truck won't even shift into Neutral. This is my first Ford and I have to say I'm not impressed. I've spent more on this truck in terms of repair fees than all my Chevy Silverados combined.

I would open up a new thread for this. These are two different engines and trucks entirely - like many generations apart.

As far a brand loyalty, everything device has issues. You just got lucky on the other trucks.