[richo916]

Hi
The speedo on my 1996 1.3 ford ka became very iratic. One minute It would not work the next it would work but wobble, so I changed the speedo cable. This got rid of the wobble on the speedometer but it still only works every now and then and when it does work it wont kick in untill you hit about 30 mph. Also when I looked under the bonnet there is a wire coming from the speed sensor that isnt pluged into anything is this right?

Any help would be greatly apreciated

[Rolebama]

The speed sensor should be plugged into the circuit. However, it may have been disconnected if it was faulty. A faulty sensor can cause engine 'problems', and it could have been disconnected as a fault finding aid.
As to your speedo, it may be worth checking the drive unit in the gearbox. I seem to remember it is a 10mm socket to take the securing bolt out and the nylon drive gear lifts out. (After disconnecting the speedo cable and speed sensor.)

[richo916]

What kind of engine problems would be common from this fault? have since plugged the cable back in and does not appear to be any different, however only started up and moved down the drive. UNscrewed the speedo cable and sensor and they appear to be working as they make the speedo needle move but where exactly is the securing bolt for the drive unit?

Thank you so much for your help

[Hometune]

Normally the wire from the speed sensor is disconnected when there are stalling issues when the vehicle is moving. Quite a common dodge because when its disconnected the engine ECU doesn't know how fast the car is going. You may well find that on a journey the car will cut out at junctions and roundabouts but not when you are sat on the drive just revving it.
As Rolebama says the sensor is held by a small bolt (10mm socket).
If this part is okay then the speedo head will be at fault.