tail/brake lights/wheel speed sensor

I have 2005 dodge grand caravan sxt the stow and go and I had a tail/brake
light bulb go bad on the drivers side so I changed it and everything was good.
Now two days later had the same problem on the passenger side so I checked
the bulb and it was blown and when I pulled the bulb holder out there was one
contact that was solid rust so I cleaned it up along with the contacts on the
inside of the lens itself. Well as i was cleaning the lens I noticed rust spots
underneath the main plugin in the circuit board well i put the bulb back in and
put it all back together and everything worked. Well now things got screwy
sometimes the drivers side parking light won't work but brake light does work
and the passenger side will be fine and then at times it will switch sides and do
the same thing and the blinkers don't blink fast on the side that is out. I know i
need to get a new lens and bulb holders for the passenger side. But I guess is
there anything else that I should check or do? What is the easiest way to find
out which speed senser is bad same vehicle with abs all the way around and
the speed sensers are in the bearings?