Well, I was coming home from work today and the speedo needle just dropped and the tranney came out of overdrive. I have had this happen before and all I had to do is thump the front of the instrument cluster and the needle work just jump up to speed and the tranney would go back into over drive. Today of course thumping, hitting and yelling did not fix it. I got home and pulled codes and there wre none. I checked all of the fuses and I am going to Ford to pick up a VSS in the morning. Is there a way to test the sensor? I don't think it is the vss. I think the speedo itself is bad.Can the speedo it self go bad? I pulled the cluster out and I do not know which wire goes controls the speedo its self. Am I right or can some one tell me what to do next. Oh, I did a search and did not find any help. I like the search feature myself it keeps me from haveing to type that much.
I changed the vss/abs sensor in the top of the diff. I checked the tone ring and it seemed to be in good condition. I recplaced the insturment cluster with one out of the juckard. Nothing seems to work. I there a way I can check to see if the speedo is good or not? What else might it be?

 

i know you check the ones under the hood?

 

I just had the same problem. The wiring from the VSS got cut on something while I was driving down the road. This could be easy to overlook. Follow the wires out of the VSS and check for any damage to the "pigtail". May not be the same problem but sounds like it could be. I almost replaced the VSS when I saw the damaged wire. If this is the problem make sure you solder the wires back together (no connectors). The resistance can't change or it still won't work at all. Don't ask me how I found that one out. Good luck. Let us know if you fix it.