removed negative cable on 98 dakota to change oil pump, now lights flash and motor wont start when i rehooked battery, HELP

 

Does it crank? Or do you hear nothing when you turn the key

Clean your battery terminals. Then charge your battery for a couple hours, then try again. Its possible it got drained somehow, and now doesnt have enough cranking amps. The reason i suggest this is because my sisters beetle will crank just a liiiiittttleee bit, and all her lights will flash and go crazy but it wont start when her battery is dying/dead.