Don't use a universal set of crimpers and hope for a good connection. Using the right tool makes the difference between a good job and a great job; especially when crimping electrical connectors. MSD Weathertight Crimp Pliers 3511.
MSD 3511 Weathertight Crimp Pliers
MSD Ignition 3511 Weathertight Crimp Pliers For Use with Weathertight and Seals
MSD Ignition Pro-Crimp Dies For Deutsch Terminals
MSD Ignition Pro-Crimp Ratcheting Crimping Tool with Interchangeable Jaws
MSD Ignition AMP Lug Terminal Crimp Jaws for the Pro-Crimp Tool, 10-22 AWG
3503 MSD Crimp Tool