'01 2500 Hd Abs And Break Light Flashing

[lefty marcel]

A couple days ago, i was retrieving my boat from a lake. My truck was not in the water, but I put it in 4 wheel drive because i was spinning going up the ramp. I then set the emergency break to tie down my boat. When I released the emergency break, the abs and brake light were flashing on and off. The abs light flashes for about two seconds and is off for about two seconds. The break light is also flahing, but there is no rhythm for it at all. Also, only once, my speedometer dropped to zero and the battery light illuminated in my message center. This almost immediately corrected itself and hasn't happened again. Can anyone give me an idea as to what is happening?

 

Thanks