2003 Dodge Ram 1500 4.7 won't start

My truck has 45000 mi. on it. Everything was functioning properly the last time I drove it. The following day it would not crank over. The dash lights all flash several times and I hear a light constant clicking under the dash when I try to turn it over. Like a clock...click-click-click.The battery test panel looks dark at a glance but has a green dot down inside it. I gave it a full trickle charge. Then tried a boost start. The dome lights go out, the head lights come on dimly, dash lights flash. To me it acts like a relay is tripping everything off. None of the interior lights, radio or blower motor will come on unless the charger is on and shut off when I try to crank it. Any ideas? I appreciate your help.
Thanks,
LKT1710