Chrysler Repair: speedometer quit after spark plug change, crankshaft sensor, speedo needle

Question
changed sparkplugs on 2001 town & country and speedomedor stopped working any idea why.

Answer
Hi Steven,
I don't see any possible relationship between the two. The speedo get its signal from the crankshaft sensor via the digital data bus wires that carry almost all the other engine information so if it lost its signal from the sensor the engine would not run well either. And the power to run the speedo also runs all the other gauges. There is no plausible explanation I can see other than a chance failure unrelated to changing the plugs.
Roland
PS: It may be that the speedometer needle is struck behing the pin at '0'. Try this self-diagnostic test to correct the speedo function: With the ignition 'off' press and hold the trip odometer reset button and while holding it turn the ignition to the 'run' position. Continue holding the button until 'sof' appears in the odometer window. Release the button and the cluster will run through a series of self-tests which will possibly reset the speedo needle so it functions again properly. When the test are completed, if everything is OK, the code 999 will appear. Any other number is a code for a problem so let me know what that might be. Then see if the speedo works again.