Toyota Repair: ignition problem, battery cables, battery connection

Question
1991 4runner with no problems starting. Tonight I went to start the truck and when I turned the key the dashboard lit, then all power went out in the vehicle. I wiggled the battery cables and the power was restored. Attempted to start and the issue replayed itself. Would even a weak battery connection cause all power in the vehicle to go out ?

Answer
Yes it seems that the battery connections at the terminals may be corroded or loose, check the terminals and make sure they are not corroded, if so remove them and clean them with a wire brush and some battery cleaner available at the autoparts store, reconnect or replace the terminals as necessary.