Intermittent no start no crank on warm days 2008 v6

[94Fexplorerxlt]

When I take short trips and the temps are 75F or higher my explorer doesn’t want to start , no crank no nothing no sound . I just replaced the starter and alternator . Battery is like 3 years old but it’s a good good 800 CCA . I suailly swap around the relays and it eventually starts . I’ve replaced these relays with OEM surplus stock before , has anyone had this happen before and figure out what it is . It’s annoying during the summer dealing with this especially when getting groceries on a hot day.

 

[94Fexplorerxlt]

I'm still having this issue but on top of this I have rough idle like it drops rpm and acts like its going to stall . Also I was driving other day and engine shut off and I lost all power steering and it wouldn't start back up for like 10 minutes. I've used an OBD scanner and my engine temp is 185F so I dont think its overheating. This is very annoying as I dont want to scrap this vehicle but I cant trust it anymore . There's no codes or anything . Mechanics dont know what to tell me . Anyone have a solution ?

I've changed EGR valve, PCV , Crank shaft position sensor , cam shaft position sensor . Nearly everything

 

[94Fexplorerxlt]

I changed the ignition switch and I think it fixed everything . This is like my third time changing it but these symptoms were not present the last times I did so I didn’t think of this being the culprit . Just wanted to update Incase somebody else finds themselves in this situation . Hope it helps!