I need y'alls help
 

I have a 2016 mustang GT I just bought a couple weeks ago. I went to start it after the car sit for 7 hours. All the gadges and screen and ac wasnt on but car was running. Turned car off and back on again. Still the same thing let it run for a couple seconds and everything came on and ac kicked in. But the traction controll light was on and showed it was off also hill start assist shows it was disabled.Drove the car for 10 min stopped the car on the road turned car off and started it traction controll light went off and everything was normal. Any ideas ?

Sounds like a relay sticking somewhere.

That SOMETIMES happens in long term test cars for Car & Driver magazine... they'll report something just like that, it appears once and never appears again.
2016 should still be under warranty. I'd not hesitate to make an appointment with ANY Ford dealership to see if they can hook it up to the diagnostic machine...see if any DTC's were recorded.

It also maybe...perhaps could have been just the cars PC running its own diagnostic... I'm not sure Ford pushes over the air updates?

So many computers on cars these days...who knows!

wouldn't the ac relay and the dash and headunit be under diffrent relays ?

I'm thinking about sending it in but I just bought the car from a chevy dealer in Miami and I live in cocoa FL 3 1/2 hours away. Plus I'm not sure if the guy who owned the car did anything to void the warranty. It has a short throw shifter in it but carfax shows it was done at a ford dealer plus the clutch was replaced and slave master cylinder all done at Ford dealer. Not sure if it's a upgrated clutch or not car only has 18k and clutch was done at 7k miles.

If the issue returns, just take it to your local Ford dealer. The type of aftermarket things it sounds like the previous owner did will not void the warranty on electrical issues. The dealer won't really care where you bought it either.