In this video I got a system sensor i3 with 5 WIRES that are unmarked and I don’t know how to wire it.
That is a 2W-B specifically, which means that it’s a basic 2-wire i3 smoke detector that requires a matching 2-wire base. However, before you go & buy one, be warned that they’re one of those kinds of detectors that require current-limiting, so if you try powering it off some 9V batteries or a homemade panel (as well as actual FACPs that aren’t said to be compatible with it), you’ll very likely blow it up. You would have been better off getting a 4-wire 4W-B instead, because they can work on non-current-limited power, such as 9V batteries.
Okay as mentioned by other people, this isn’t a good idea to wire as is without some current limiting power supply (which not even I knew the 2-wire I3s needed), but 1/2 is positive, 3 is negative, 4 is remote indicator positive, 5 is remote indicator negative
(You can ignore the remote indicator stuff if you aren’t going to use one)