2013 Outback won't start?

SOURCE: Subaru Electrical Gremlins

turn head light on and try to start car if they dim way down replace battery or connect a volt meter to bat check voltage while cranking. it must be 12 volts or higher.

SOURCE: 1989 Subaru Gl Wagon At

does the vehicle have an alarm system??? possiblly causing fault, or if the battery is fine, check the main fuse in fuse box located in the engine bay beside the battery,

SOURCE: Recently, my wife's 1998 Subaru

I had the same problem on our 1999 Forester after replacing the battery. Here was the solution I was given by Subaru Santa Cruz.
1) the key to the ON position where all the dash lights up. 2) disconnect the NEGATIVE battery terminal. 3) wait 15 seconds then reconnect the the battery. 4) start the engine from the ON position.
If this doesn't work, the car must be taken in for repair.

SOURCE: 97 outback legacy; won't start

not sure if this will help, but I recently changed the engine in my subaru and changed battery + starter also. Would start but then not restart once warmed up. Turns out the engine ground got forgotten, had that hooked back up after banging my head on a wall for a week and it runs like new

SOURCE: battery goes dead intermittently

You have a parasitic drain problem.

Have any aftermarket components been installed?

D/C the negative battery cable and hook an ammeter between the battery terminal and the cable. Anything over 50 milliamps is too high. If it is over 50 milliamps:

Go to each fuse box and pull 1 fuse at a time, check the change in the amperage reading, then plug it back in. If the reading drops to normal levels (below 50 milliamps) when a certain fuse is pulled, the problem is in the circuit powered by that fuse. Find the different components powered by that fuse and check them.