The speedometer of any vehicle is an instrument we all take for granted but like any component on the car it can be very costly when it fails. Everyday driving requires the speed limits of a given area or road are kept to, without a speedometer this is impossible. A speeding fine and points on your licence last for three years and will increase insurance premiums. To change the speedometer on a Corsa is a job you can undertake at home with some basic tools and a bit of patience, this will save hefty garage bills and hefty fines.
Park the car in a safe place to work, lift the bonnet and disconnect the battery, you only need to disconnect the positive terminal of the battery. Make sure the connector is far enough away from the battery so it won’t move back in place and make the circuit live.
Take a Philips screwdriver and remove the three securing screws from the top plastic dashboard surround above the instrument cluster. Then remove this panel you will now see the speedometer unit.
Use the Philips screwdriver and carefully remove the four screws (one in each corner of the speedometer unit) do not drop a screw behind the dashboard. Once the screws have been removed gently ease the speedometer unit forward toward the steering wheel, care must be taken as there are wires attached to the rear of the unit.
Release the wire loom from the multi plugs at the rear of the unit, best to use a small screwdriver to pry the tabs that are at each side of the multi plug then pull apart. There are three multi plugs on a Corsa so repeat the procedure with all three plugs the speedometer can now be removed.
Take the new speedometer and carefully put in place, re connect all three wire loom plugs and make sure they are fully clipped in (the plugs will only go together one way). Push the unit into place and secure with the four screws, tighten screws in a diagonal sequence and ensure no wires are trapped anywhere.
Replace the dashboard surround and screw back with the three retaining screws, make sure all screws are tight; this will prevent any rattles later.
Reconnect the positive terminal to the battery and make sure you have a good tight connection, close the bonnet and take the Corsa for a test drive. You will now have a working speedometer.
Always disconnect the battery if working with any car electrical system. This job is easier if you are sitting in the driver’s seat. Across the Corsa range there are small differences in how the instrument panel surround is removed, check manual for the model.
Ensure the battery can't accidentally re-connect while you are working. Make sure the hand brake is fully engaged while working.