2006 f150 5.4 triton no start! gauges not working either please help

[DWG2013]

Hey guys,
My sister has a 2006 F-150 5.4 Triton, we put a SCT Livewire tuner on it about a week ago. It has ran fine, started like normal. She went outside this morning and it would not start, gauges would come on or anything like the battery was dead. We put jumper cables on, but it did not change anything! we then changed the battery and after that it finally started (after cranking for about 10 seconds)

We took it pheasant hunting around noon today and started it many different times driving from spot to spot... Then we walked back to the pickup after it set for about 15min and it did the same thing as it did in morning, however this time we did notice that the key commands worked (horn alarm, doors locking and unlocking) just fine. The lights would also turn on, I did not really notice if it did these things this morning or not, but I did really not think to try them.. my dad then crawled under the pickup and tried to start it by jumping the starter, (it would crank fine , but not fire)

If anyone has this problem please help us! or at least some direction as where we could start looking.
thank you very much!