I have recently had some work done to my 1998 gmc jimmy 4d and now the speedometer or the odometer doesnt work! the mechanic replaced the transmission. i checked for a blown fuse, but all were good.
Could there be a connection loose or forgotten to be put back together?
Thanks for the help.

 

Probably forgot to connect the VSS sensor. It is located in the tail housing on the transmission (2wd) or transfer case (4wd).