Replacing TH8321WF1001 with nest

[Narusegawa]

I am trying to hook up my nest 4th to my system, but based on my research, i am getting some conflicting information. 

I have been able to identify where most of the cables would go, except for the two S1 cables, i am unsure what those are or where they would go. I was hoping someone could lend me a hand. 

for some reason i am unable to share pictures on here.  

[Narusegawa]

being that i was unable to post pictures, i added one to imgur, it will show the current connections.  
https://imgur.com/a/eUI41Z4

[CoolingWizard]

@Narusegawa ,

The two wires labeled this one and S2 are for the outdoor temperature sensor and the heat pump system. Those are not needed by the nest thermostat so just tape them off and tuck them back in the wall.

AC Cooling Wizard