I only have rear wheel ABS I just changed front rotors and pads and now my ABS and parking brake light is on. What's up with that?

 

You may want to check the level of your brake fluid. If it is low in the master cylinder it will cause this problem to occure.
Also I am told that the ABS computer has to relearn certain things when a brake job has been put off for a while. I dont know how bad the brakes were on your truck but my friend that works as a tech for a ford dealership told me that, true or not I dont know?
Good luck with your truck.

 

Yep I figured out the low level. I siphoned some out and added clean fluid I guess I let it get too low when I did that. The light did go out the next time I started it.

I do my front brakes every year, this time though the inner pads wore really fast and one went down to metal. I just replaced them in June of 08, same $50 pads from NAPA I've been using so I don't know. I went with new rotors and a different brand of pads this time.