# 280ZX Speedometer Problem



## kdgraben (May 5, 2004)

I just installed a replacement speedometer in my 1981 280ZX and the cable is in good condition, the odometer works but the needle does not move. There are also 4 wires connected to the speedometer, is there something else that could be wrong? This is driving me nuts.

Thanks,
Karl 
:cheers:


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## Zen31ZR (Mar 24, 2004)

Likely then that your replacement speedometer is bad. Those 4 wires I beleive are for the ECUs use.


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## icice9 (Dec 18, 2003)

your replacement spedo is bad. if your odometer turns but your needle dont then thats mostlikey a bad speedo...


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## kdgraben (May 5, 2004)

[email protected] said:


> Likely then that your replacement speedometer is bad. Those 4 wires I beleive are for the ECUs use.


Do you know how the speedo works? There is some type of permanent magnet that spins in a brass colored cup that is attached to the needle. I have never seen anything like it before. It seems like it could never go bad. I took it apart and everything is in working order. Do you know about this?


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## Zen31ZR (Mar 24, 2004)

kdgraben said:


> Do you know how the speedo works? There is some type of permanent magnet that spins in a brass colored cup that is attached to the needle. I have never seen anything like it before. It seems like it could never go bad. I took it apart and everything is in working order. Do you know about this?


If the odometer works but the speedo does not , then you can eliminate the cable. Which leaves only the speedo itself to be the problem. Magnets can be demagnetized , either by impact or over time they become weak. All speedometers work off of the spinning magnet principal , have since the car was invented , basically. It may not be the magnets fault , the needle may be jammed or some other part out of place. If nothing is obvious when you look in there at the cup and magnet stuff , then I'd say replacement is in order.


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