Hi Laurie
My car is fitted with a Ford Zetec 1.8 engine and a Ford MT75 Gearbox. I think I read somewhere your car is fitted with a Rover Engine and I don't know anything about them or what gearbox is fitted. I am absolutely sure that other people on this Forum would be able to tell you.
Turning to your photographs, the fourth photo showing the speedo connector looks very similar to mine. I am pretty sure that the yellow wire is the signal in from the sensor and goes to Pin 8. The component in the sleeving goes from the yellow wire to two black wires, which I think are Pin 3. That would be the ground connection to the instrument.
You can check the pin numbers. Hold the speedometer the correct way up i.e. odometer at the bottom, look at the rectangular socket at the back of the instrument, there are two rows of four pins. The pin numbering starts at the bottom right hand corner which is Pin 1 to the bottom left hand corner which is Pin 4, then from the top right hand corner Pin 5 to the top left hand corner Pin 8.
Your third picture shows a connector with a number of wires. If this is the speed sensor connector the sensor would need three of those wires and I am going to guess that the other wires are associated with the reverse light switch, which is probably also in the gearbox. It wouldn't be a bad idea, with the car battery disconnected, to disconnect and reconnect this connector a few times to try and clean the pins.
The chances are that the yellow wire in this connector is the one that carries the sensor signal. You can check this. Switch your multimeter to its lowest ohms range, connect the two meter leads together and the meter should read somewhere between O and 0.9 ohms, make a note of the reading. To be safe disconnect the car battery negative terminal. You may need help but hold one of the meter leads on the yellow wire of the speedo connector and with the other meter lead back probe (you might need to use a safety pin) the yellow wire in the connector in photograph 3. If the meter reading is the same as you saw when you put the meter lead together then it is pretty certain that these two yellow wires are connected. If this is the case you could then normalise the system by plugging the speedo back into its connector, reconnect the car battery negative terminal and then, with your multimeter set to measure DC voltage say 20 volt range connect the negative meter lead to ground and the positive to the yellow wire in the connector in photo 3. With one of the cars back wheels jacked up and the ignition turned on, spin the wheel and this voltage should be changing up and down as the wheel rotates. Hope all this makes sense.
Best of luck
Regards Tony
