I was having issues without no taillights so I went got a bulb and while car was running I was changing out bulb checking wires and whenever I pulled up trailor wires the connecter touched battery killed car instantly and its say low fuel power steering and anti theft light is on and my power locks wont work I've fully charged batter and still wont turn over what do I do ?? PLEASE HELP ME!!

 

Check the trailer wires for a direct short, check the master fuse by the battery is it blown or just loose. Check the battery terminals and the ground connection, all tight?