1999 SAAB 9-3 repair Question engine wont start

1. I turn the key and the engine cranks but it doesn't turn over. My wife drove it to the store and back with in 1 and half hr when she parked it, the next day it wouldn't turn on just cranks and thats it.

2. I was wondering if does it have to do with the climate, because we use to live in the bay area of oakland CA and now we live in Sonora CA the climate there is a little high but the car ran great for a month the saab is a turbo I see the option for it is not there.

3. Is there anything I can do? I have a OBDII module and was wondering if it would work on it, I dont want to plug it in because I dont know where it is and I rather ask for advice before I plug it in.

thanks Miguel