Erratic speedometer reading
 

My speedometer jumps around and wont give a steady reading.
where is the speed sensor located on a 1985 318 with 4 banger
or any suggestions on how to repair this problem?:confused:

yea, the pulse generator for the speedometer is located in the back of the rear diff. follow wire ceck for rips, tears, in casing. and tight connection.

Jav is right. Jack the rear of the car up and look on the back face of the differential. The speed sensor is located on the passenger side of the diff.

One more thing, you may also want to check the ground strap on the car. When resistance builds up in these straps, it can cause the guages to go crazy. In your car, the battery should be in the front. Check the resitance of the ground cable.