SO shortly after I installed the magnaflow 15749 dual catback exhaust on my truck I had the ABS light come. I looked undernieth and saw that some wires where layed up against the pipe and burnt a flat spot on the plastic covering that wraps the wires, so i zipped tied them away from it.

After i zipped tied it away the light came on next time I started and was on till I shut it off again. The next time I started it, even though it was a short trip, the light never came on. Then when I started it again the light came again and comes on every time I drive it now but some times it is delayed a little bit when I start it.

From what I have searched it is the speed sensor on the rear diff. It is all wheel ABS and I guess the code can't be read and I dont feel like taking it to Ford at this time, for them to read it and tell me its the sensor if it is

So basically what I am tring to ask here is, does this sound like it would be that sensor in the rear diff and if so what does it look like and where is it. A picture of it would be greatly appreciated. I have a 2000 7700 4x4 series if that makes any difference. Thank You in advance for your help

 

Id be looking in the area where the wires are burnt. Its very possible you are no longer getting a good connection and that is why the light is coming on.

 

You could have fried the sensor when the wires got burnt. I've never looked on the newer trucks, but the sensor on my Bronco was on top of the rear diff housing. There's an exciter ring next to the ring-gear that the sensor reads.