I just had my trailer plug rewired. when i plugged the prong up to the trailer everything seemed fine, then when I start driving with the trailer my ABS light starts flashing, my brake lights and turn signals all of the sudden don't work, and I can't shift into drive from park, I have to shift it into neutral before I start the truck in order to get in to drive. please help!!!!!!!

 

Problem solved, I figured out that the trailer was not properly grounded and it blew the brake and turn signal fuses. Why can't you shift into drive if a fuse is blown? That's just ridiculous! Oh and while I'm on the subject what is the proper way to ground my trailer?

 

I didn't read this post before. Make sure the brake/ turn wire is not touching the trailer anywhere!

 

You have an automatic with a transmission lock. You need to have the brake on to shift out of park. The brake signal is taken from the brake light circuit, not hydraulic pressure. So, if the fuse is blown, it doesn't know you have applied the brakes.