I was driving to work, a guy pulled up beside me and told me I had no brake lights. I traced it to stop light switch. I replaced switch, now ABS Brake light lights come on every so often? no adjustment on switch. what up? also shifts from overdrive to drive repeatedly anyone had this problem?

 

Hmmm thats a weird one. Did you have the light scanned to see what the code is?

 

My abs light came on when my master cylinder went out.

 

in and out of overdrive? sounds like it could be your tps perhaps mine did that and i replaced mine world of difference volt test the tps see if its reading low volts

 

Yeah the overdrive thing could def be the TPS. Check here about 1/3 of the way down the page:

Dodge diesel maintenance tips