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The speedometer needle on my Opel Corsa most of the time lies at the top of the scale (200) and doesn't move during driving. Sometimes, however, the needle rests at a different number, such as 140km/h and shows the speed accurately when driving, only with an offset of 140km/h in that case. Over the next days the baseline speed decreases, until it shows 0km/h when standing and shows the correct speed whole driving. The following days, the needle is back to 200 and doesn't move whole driving.

From what I read, the problem could be a fuse for example. It looks to me as if simple the needle isn't fixed properly to the axle in the dial and only sometimes grips and shows the speed. How can I fix this?

DK2AX
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    If it's a mechanic speedometer, the needle might be bend or it slipped to a different angle. Mechanic speedometers work with friction, so dirt, dust or other stuff in it can spoil the working. – Bart Nov 03 '16 at 11:21
  • @Bart I'll try to remove the front glass on the instrument cluster and check if there is dirt etc. Is it safe to glue the needle onto the axle in the zero position? – DK2AX Nov 03 '16 at 11:48
  • I'd google your specific model first (type, year etc.) to make sure it's a mechanical one. If it's an electronic one, you can save yourself the effort. I doubt you can repair that, if it's the meter itself that is broken. Cause could also lie in the signal that it is (not) getting if it's electronic. To remove and reset the needle manually may not be the best solution. In this case i'd look for a new speedometer, 2nd hand. I personally use my GPS/navigation as speedometer as it is more precise. – Bart Nov 03 '16 at 12:22
  • I'm betting on the being electronic and having a difficult time calculating/finding 0 – rpmerf Nov 03 '16 at 12:38
  • @rpmerf If it stays at a position other than 0 even with the car completely shut down, doesn't that suggest there is a mechanical failure? – Bart Nov 03 '16 at 14:52
  • Its possible. I'm thinking there is a servo is the back that read the position, zeros out at startup, the does a calculation like (zero position) + ((position increase/mph) * mph ) which is why it just offsets. All of this is theorizing, no real experience here. – rpmerf Nov 03 '16 at 14:57
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    What's the year on the car? Is it a cable drive speedometer or is it electronic? I don't have access to any service information outside of the USA but someone else might. The speedometer is either driven by a cable and gear in the transmission or an AC or DC signal from a sensor on the transmission. If you can verify the signal/that the cable spins, you can isolate the problem to a specific area. – Ben Nov 03 '16 at 21:35
  • I have a less serious version of the same issue in my transit. I'm fairly certain it's the gauge sticking or slipping mechanically. We used to have a corsa and I think the speedo flipped to 100% when when the instrument panel booted up, which could contribute – Chris H Mar 06 '17 at 13:20
  • I would oil the cable. Use a drop or two of 0w40 – danny117 Apr 05 '17 at 18:26
  • Was this ever resolved? Sadly all we can do is guess without more specific information. Like the year of the car. With that and info about the kind of speedo mechanism this is, there would be a place to start. Please don't attempt to fix this with random hacks until there's more info available. You could very well make it worse. – cdunn Apr 11 '17 at 02:46
  • No, it isn't resolved yet. It seems if it is "fixed" and the needle stays below 100 (the top point on the dial), the speedometer shows the correct speed. As soon as we drive on the highway and the speed is sometimes above 100 km/h, the needle does what it wants on the next day. I am now mainly using my navigation app to show the speed and stay below the speed limit. – DK2AX Apr 11 '17 at 14:09

2 Answers2

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Often times the speedo cable just needs lubrication. You can do this by disconnecting the speedo cable at the back of the speedometer and dropping some oil down the cable. Happens on Miata's all the time.

RDS_JAF
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It sounds like the speedo head has failed. Try disconnecting the cable from the back of the head, the speedo should then read zero'ish mph.. If not the head has failed.

Orb
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