This is pissing me off!

My wifes 1996 subaru outback won't start when she stops it after driving for a while. turns the key, nothing happens, just beeping. then in like 30 minutes, turn the key and it fires right up, i pulled the 12 pin harness for the inhibitor switch, and tested for cont. all ok. put it back together, tightened the battery terminals. here's what i'm thinking, crank sensor, ignition switch, temp sensor bad. has anybody else experienced this? all help is greatly appreciated.