*help* 2012 starting issue
 

I'm neither a mechanic (nor knowledgeable about the internal combustion engine) but I believe ... it takes battery power to heat up those glow plugs; what if they're getting weak?

As I explained earlier, I'm not technologically advanced - so I'm not familiar with your "at" reference - to me that means automatic transmission.

I would put a voltmeter on the batteries and see what they measure before the ignition is turned on and then when the ignition is turned on.

As a test, you could put a battery charger on the battery when the temperature is below 40° F. If the engine fires right up then the batteries are suspect.

While you're checking the batteries double-check that their connections are clean and tight.

Okay. Thank you. It is the weirdest thing. I have take it to a couple of mechanics to have them look at it, and neither can figure it out.

I have a 2011 F350 and also have a starting issue. I don't believe mine to be temperature related, but I can't really say for sure. My truck seems to fix itself magically. I have had it do the NO start about 4 times now, and have had it at the shop 3 times. They cannot get it to do it while they have it. It is very frustrating!
They have verified batteries are good, starter good, alternator good, ALL connections are snug. It is an electrical gremlin so to speak. If it does it again (and it will) I plan on towing it to them while it won't start, and go from there. The problem with that is......it will start after sitting for awhile. Mine has power with the key on, but no crank when it happens.

Maybe a bad relay?

I swapped out my relay, and it didn't help. But perhaps it might for the original poster?

I will check the relay as well, but pretty sure that was what the first mechanic thought as well and checked it first. Mine will power up with the key on just will not crank as well. Super frustrating. But I will change out relay again and see if that does anything.

Kyle, does your truck seem to fix itself, and end up starting if you try it long enough? Mine will do that, and there doesn't seem to be a pattern to it. It has gotten to where I can't trust my truck, I never know when it's going to NOT start!

The one thing, that the mechanic did fix, was a wire was really corroded that comes off the starter, as sort of a "test wire" for diagnostic purposes only. It doesn't affect the power for cranking. When the truck started, we thought it was fixed, but a few days later, I had the NO-start issue again, and back it went to the mechanic for a week. They were never able to get it to NOT start, so I brought the truck home!

Pretty much mine is the exact same issue. I have at least narrowed it down to, and sorry for my lack of better explaining it, but if the glow plug indicator light doesn't come on, then the truck will not start. As soon as the light comes on, it will start. I can normally just turn the key one turn to make the glow plugs come on, and if the light doesn't come on turn the key back off and try again. Sometimes it takes 10-15 tries, but as long as the temp is above about 40 degrees, it will eventually start. I haven't tried looking for a corroded wire, but that was going to be my next step after replacing the relay.

Kyle, my truck isn't throwing any codes at all when it happens. I haven't paid attention to the glow plug indicator on my dash, but I do know it's not temperature related, my issue started in September when it was still very warm. I think between the two of us, we can figure out our problem, and share with the other guy haha.