Speedometer stuck at 20-30

Just today my speedo on my 2000 windstar lx crapped out on me. As I accelerate its very sluggish and doesnt keep up with my real speed. When im going ~50 it shows up as ~20, When i go ~60 it shows up as ~30, but it wont go above 30 no matter how fast i accelerate(I can only go so fast on public roads =P ) I was wondering if anyone could help me out with this problem. Also today at the same time, my ABS light came on. I tried topping it off with brake fluid but that didnt help. I think the speedometer problem and the ABS light are somehow related because they came on at the same time

I would check the harness connector, etc, going to the "speed sensor". #9E731. On the transmission top near the RH drive axle. If you want to remove (one bolt) this sensor, be sure no crap/dirt falls into tranny.

I have a 96 windstar that had similar issues. Speedo would lag behind during acceleration topping out around 35-40mph. After a shortitme it would jump up to the correct speed. Condition deteriorated over a month or so until it began erratically bouncing all over the place. Took it to a Ford garage and they removed the Speedo from the dash and sent it to a speedo repair shop for cleaning. Cost $200 becase Ford garage was the middleman. I suggest calling a speedo shop and asking them to work on it directly.

I would guess it to be your head unit