So I have a 2004 GXP. Only had it for about a year. Had the bouncy Speedo when I got it. Replaced the output speed sensor and it fixed it for a while. I have since replace all the stepper motors as well. The other day the Speedo started the same weird behaviour as before. So I figured since the speed sensor was a cheap one I got a better quality one and changed it again. I also changed the connector. First I put the connector on with crimp connectors but when I drove the car the speedometer didn't even register. So I redid that by soldering and heatshrinking the electrical connection. Immediately took the car on an hour and a half drive and it was perfect for an hour and 15 minutes then the Speedo started bouncing around again. Then the next time I started it, the Speedo needle didn't move at ball again. Registers 0.


Could it be the input speed sensor? Or something in the transmission? The transmission shifts hard when the speedometer is not registering speed. I'm at a loss...

I would first check wiring from the servo to where it terminates. - continuity test -

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poverty forces one to do unorthodox things

2000 SSEi
past rides:
1996 SSEi
1992 GTP
1987 Grand Am

Also, look at the speed sensor end...is it getting full of metal shavings on the magnet?

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A temporary fix does not exist. It becomes a solution until it needs to be fixed again.

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