For the past few weeks, my daughter's 91 350SDL has had intermittent - no start (won't turn over). Everything on the car is powered up, but the starter won't engage. Then after a while, it will start normally. Today I tested the battery and found it to be weak so I replaced it. Now I have no power at all anywhere on the car. My test light shows hot at the battery cable and the battery tester shows full charge. But no power to anything on the car.

Is there a master fuse that might have blown? Or any other suggestions? I don't have any power in the fuse box. Thanks.