The problem with cars is that they’re notoriously unreliable. Even the most trustworthy cars from the most trustworthy manfacturers will develop problems now and again. And perhaps the most frustrating types of car issues are those that have no clear cause. Got a flat tire? Replace it. Car not starting? Check the starter motor. But a problem where your speedometer drops to zero randomly can be very hard to pin down. It’s also very dangerous – not knowing what speed you’re doing when you’re going full speed on a highway isn’t easy for anyone! So let’s take a look at the possible reasons that your car’s speedometer is dropping to zero and staying there.
Water damaged wiring
With the number of car loans available these days, it’s never been easier to get your hands on a car. But not everyone knows how to deal with the problems that come with it, particularly not electrical problems. There’s hundreds of feet of cabling in every single vehicle, so it’s no surprise that problems can occur – especially in wet weather. If your speedometer has been dropping to zero, it’s possible that your wiring has been damaged by water. When water comes in contact with certain connections in a car, it can cause blown fuses, each of which controls something different. If the fuse that controls your speedo is blown, it probably won’t work. In this case, replace the fuse and have your wiring looked at by a professional.
A faulty speed sensor
This is the most likely explanation for a speedometer being glued to zero, but it’s not always cheap to repair: a faulty speed sensor. If you bought your vehicle with car finance, you may already be covered for mechanical issues, so one of the first things to do in this case is check with your car insurer or car credit provider – they’ll let you know whether you’re covered for mechanical damage to the car. On most vehicles, the speed sensor is located near the front axle, and its job is to judge the speed at which the wheels are turning. If it’s broken, it won’t report speed properly – or at all. One good tip is to choose the right vehicle financing option when you buy future vehicles, to ensure you’re covered in the case of a broken speed sensor.
A malfunctioning ECU (Engine Control Unit)
Just like us humans, modern cars are equipped with a ‘brain’ of sorts. This ECU, or Engine Control Unit is essentially a computer that keeps an eye on every bit of the car’s operation: oil levels, temperatures, water, condition of the brakes, and speed. This last point is the important bit: the ECU is responsible, at least in some cars, for reporting the speed of the vehicle from the speed sensor to the speedometer. If there’s a problem with the ECU, this process can be interrupted – meaning the speedo either reports speed inaccurately (not good with speed traps around), or not at all. To fix the ECU, it must be reprogrammed by a professional mechanic. They will also be able to carry out a full diagnostic of the ECU to check on potential problems. Usually these can be done at the same time in the space of one visit, and unlike a faulty speed sensor, you shouldn’t need any extra parts to fix the problem.
If your car is suffering from a speedometer that keeps dropping to zero, the first thing you should do is to follow the steps above. Check all of the fuses in your car, in particular, because fixing a problem like this is often a case of simply replacing a blown fuse. The fuse box in most cars is usually behind the glove box or under the hood somewhere. If this fails, or you can’t identify the cause of your malfunctioning speedometer, you should consult with a professional mechanic in your area that will be able to give your car a good check over and find out exactly what’s causing your speedo to be on the fritz. And remember: if your car can’t read speed accurately, driving it is a bad idea, so try to stay off the road until it’s fixed.
If all else fails, and you are in need of an auto repair shop, use TalkLocal to find one local to you. TalkLocal will find a highly rated company in your area and have them call you immediately
