on my 96 f150 i got an 8.8 rear end and it has this wiring harness that goes into it what is that harness do i need it cuz i have plans to swap a 9 inch rear end

 

That goes to the ABS sensor. On some trucks it also runs the Speedometer. Unplug it and the ABS light will come on, but see if the speedo still works. Why are you changing to a 9"?? The 8.8 is a strong rearend.

 

well first the abs light is allready on and i dont know why and second 9 inch is stranger and my friend gave me one with limited slip alloy shafts and a 4 11 gear ratio so thats why and plu im goin to convert to disc brakes

 

you should keep the 8.8 9 inch isnt it all that great

 

If you want your speedometer to work then you need that plug and sensor. It is for the ABS and the speedometer.

 

yea i think im gonna stay with a new 8.8 but listen to this i went to replace that sensor and it was broke in that hole and i can get it out so i got to tow it to ford today and get them to fix it great should cost me a crap load

 

Don't tow it.. For the love of God its just a plastic sensor.. Pull the back cover off, us a punch and break up the old sensor. Clean the holse really well and install a new sensor.