'91 Ford Tempo - No start

I have a 91 Ford Tempo that was running fine a week ago. We went out to start it a few days ago, and it wouldn't start...no clicks, no sound, no dome lights, stereo or anything else. I pulled the alternator off as well as the battery and had them both tested. The alternator tested fine (15 volt output). The battery however tested bad and we replaced it with a brand new battery. As soon as the alternator and battery were reinstalled, the car started just fine, but when we returned about 3 hours later, it wouldn't start again...same issues. When we jump the battery from another car, it starts and runs just fine, but once the car turns off, it won't restart. Any ideas?

check your ignition control module ! it's on the left hand of the dist.