[TonePowerstroke]

Just replaced batterys, new oem oil filter and cap, new front cover gasket, fresh oil change, new oil pressure switch, Started after a few cranks noticed the oil gauge going down after a few minutes of warming up, turned off truck and suddenly doesn’t start , WHO knows about this???

 

[DonWarkentin]

First thing I'd do is check the engine oil level on the dipstick. Since oil pressure was going down and now won't start, could be that oil is leaking out and now you don't have enough oil to start.

 

[CarParts.com]

I agree with Don. Assuming there are no leaks, check all fluid levels. Was it actually running for a few minutes? How low did the oil pressure get?