VAN 1998 E-150 CONVERSION WILL NOT START HAS NEW BATTERY YOU HEAR A CLICKING SOUND

Double check battery connections. Also check the starter connections. Also check the negative connections on the frame and motor. If all that checks out ok check solenoid wire on starter. With key in the start position you should have twelve volts on that small wire. If not double check connections and ignition switch and relays. If you do have twelve volts then check starter connections if they are good replace the starter.