New member hoping for yall's expertise.
I've got a 2011 with a 5.0 The starter grinds occasionally before it engages. I've had it replaced 4 times. It started getting bad again so I took it to a shop last week for another starter (warranty). Now they can't get it cranked. They've put 3 starters on it, and all it does is 1 "click" Voltage shows good at the battery and at the starter with the key turned. Shop is stumped. Any ideas? I've read other threads where folks get a continuous "clicking" which sounds like battery but this is different.

 

There are lots of body-frame ground straps - Enough of them don't make good contact, then that could be just enough to mean starting or not.
Do a voltage drop test between starter ground and the neg battery post.
You can also do the positive side too.
Anything more than 1V while cranking could be an issue. That should be a perfect connection (near zero volts under load, ideally .5V or less).

I saw a vid on YT where a Ford tech had that issue with an Econoline (same idea pretty much).

These trucks also have a connector issue in the driver left foot kick panel, not sure if that can cause this issue, maybe others can chime it. I know it could cause the truck not to start (maybe not thru the starter though).

 

Consider putting your complete vehicle information (year, model, cab, trim, engine, wheelbase, _x4 drive, mileage, maintenance, modifications, etc., etc.) in your signature to have it automagically included when you post.
» Edit Signature ««« -click-
*You have to be logged-in and don't forget to [ save ] it.
**If you're posting with a non-PC ap' insure that "full version" is selected to work properly.
.

 

Very specific things to check here, this should cover all the stuff that can cause this issue.

 

Replaced the entire wiring harness for the battery and it fixed it! There was quite a bit of corrosion inside the cables. (Voltage test at the starter showed 8). Thanks guys!