2004 TrailBlazer: speedometer will not accurate it will fluctuate an...

Maybe the speed sensor that is feeding the cluster if faulty? Do you have an OBD scanner that can check for any fault codes being thrown on the vehicle?

The speedometer can fluctuate rapidly under normal driving conditions when the car's speed changes abruptly, but sometimes the needle can start swinging around the dial without any fluctuation in speed. If the hairspring comes loose or breaks, it can't hold the speed cup in place, and the result is a fluctuation in the dial. In electrical speedometers, if the circuit that counts the magnetic pulses fails, it can cause the speedometer read-out to vary from the actual speed and to shoot upward or downward without notice. If a speed sensor in the automatic transmission starts to malfunction, it can affect the speedometer and cause fluctuations. In these instances, either the speedometer or the sensor needs replacement.

stepper motor failure in instrument cluster. visit my website www.joedatech.comi have a mail in service for your convenience. or call me if you live in az.

Replace the stepper motor on the back of the speedometer. Common problem.

The speedometer and tachometer problem on your Trailblazer instrument cluster is very common on the 03-06 models. It's caused by failing stepper motors on the cluster's circuit board and can be fixed. Check out this page for more on how to get it fixed - Trailblazer tachometer problems

this vehicle has an electronic speed sensor located on the trans i do believe but im pretty sure this is your problem change it and your cured

U are going to need a new speedo, the stepper drive motor is defective in this electric speedometer, u can also have the old one repaired.

Turns out this is a common problem for the Rendezvous.
I took it to a mechanic and after he tested to see if all the speed sensors were working with his handheld computer reader, (because there is no speedometer cable anymore) He reset the needle by turning the key about 25 times as far as possible without starting the vehicle. The speedometer needle came back a bit each key turn till it reached zero. It's been working fine since.

Its a common issue with trailblazers. You can sometimes temporarily fix it by disconnecting the negative battery cable for a minute or so and resetting it, but eventually you will probably need a new speedometer instrument panel cluster (can get pricey at a dealer)

If by any chance you have a warranty, it should cover it

i have a 2004 buick lasabre gauges are not working can anyone give me an answer of how to fix this