2005 dodge magnum 2.7 will not start new battery

I have a 2005 dodge magnum SE 2.7 engine.  I was having starting issues where the starter would not kick.  the car accessories all have power when the key is in the on position.  I check the battery and  found the positive terminal was VERY corroded and the battery was bad.  replace the battery (810 cold crank amps /  1000 cranking amps) and replaced the positive terminal and negative terminal.  I use clean wire on the positive wire and made sure the connection was good.  It still will not start UNLESS I have a booster jump pack connected to the jump terminals in the engine bay.  I can hear the relay in the back fuse box clicking when I turn the key.  the front starter relay does not click thou.  I swapped the relay with the same type and no change.  the positive wire is a 2 gauge thick wire running the length of the car to the firewall and another 14 gauge wire going to the fuse box in the back.  I have check both fuses for the starter and they are good.  Any suggestions would be GREATLY appreciated.