Hey all. Been a long time reader but haven’t posted. Usually find all my answers I need and don’t have to ask.
I have a 2016 F350 XLT Crew Cab Short Bed with the 6.7L Powderstroke. Completely stock other than a lift kit.
So I had a few to do items like an oil change and brake maintenance and then my AC went out. Went and got all the parts and evaporator core.
If anyone knows anything about changing the evaporator core, you’ll know that it’s a fairly big task.
I did my routine maintenance, took for a test drive and then started on the evap core. Disconnected the batteries and in the process of fighting with it had to tend to some family stuff and the repair took me 3 days.
After triple checking myself and assembling I hooked the batteries back up and it wouldn’t crank.
I went through the entirety of the fuse panel, without checking relays (Can’t really check with my meter) and couldn’t find anything blown. Ended up taking the dash down a second time and double checking myself, cursing the whole time about what an idiot I was.
I couldn’t find anything wrong so I went back to trying to check for an electrical issue.
Ended up just turning the key for giggles and it cranked but didn’t start. Tried again and same result.
Checked codes and found nothing. Went to start and no crank.
Found out that turning the key to start within the first second allows it to crank. Any more and it won’t do anything.
Read all these forums and found where folks say, listen for the lift pump. Got no sound.
went on that trail of replacing the diode, relay and fuses just for fun, ended up costing me $145 for the same result.
Read another post where some dude had a broken wire in the connector. Also saw where the harness next to the e brake might cause and issue and went through all of that. Couldn’t find an issue.
I had to leave for a work trip so I had it towed to a reliable shop in town. He let it sit for over a week, I called him today and he said he did a communication test and all came back good. No stored codes. I decided to start swapping relays in the engine compartment thinking it had to be something there. Made sure part numbers were right and swapped a few between positions and still have the same issue.
pulled all the PCM connectors off and made sure they were ok, didn’t find any corrosion and pins looked good.
tried one last time and all I can hear when turning the key is a relay by the drinkers side kick panel.
Any ideas where to go next? I’m thinking something in the “vehicle boot/coms process check” is failing, some sort of thing like a computer when it does it’s BIOS check.
Just not sure why it wouldn’t have any codes.

 

There could be many things going on....

I would first have the batteries deep discharge tested. I suspect they will fail.

In the unlikely event they pass....I would then disconnect the forward fuel line on the engine bay fuel filter and throw a large heavy towel over the filter covering all the lines....then turn the key on and off briefly...with key off go back and check the towel...it should be soaked....if not...I would suspect either electrical problem to pump or pump itself. dont forget to re-connect fuel hose.

this should get the conversations going.