I need to know if the radio wires affect this or if the speed sensor could be bad but the service 4wd comes on and of all the time also my speedometer work and dont work are these related and how do I fix
Speed sensor sends the signal to the speedometer but it cold be a short in teh wire among other things including a bad sensor. You have two speed sensors on your vehicle. One is transmission output shaft speed and theother is vehicle speed sensor. Either one could be screwed up and bbest to have a trans guy scan it as some don'eshow up on the auto parts store scaners.