Just noticed that when Im in gear and throttle up my outside turnsignals light up dim. also when I turn the turn signals on my taillights and brake lights dim with the flashers. and still having my brake lights and abs coming on and off. Need help!

I would check to see if it has any codes. I would also check the battery to see if its holding a charge.

does the truck have a anit theft system. it may be going hay wire.

look some where just behind the left front wheel on the frame, there is two ground connections on the frame. these connections are the grounds for the tailights and if they are not good connections they will cause the lights to go dim when the flasher is on.they also ground other things which might correct you other problems.