speedometer, odometer

Been having problems with speedo on the wifes 96 grand marquis with 57000. Replaced speed sensor twice, no luck. replaced maxi fuse #8 , no luck. Car is from florida so wiring looks pretty good. Got a new head from a junkyard with 55000 . popped it in ,still no speedo along with various lamps being out. Think this one might be crap due to all the lamps and such not working. going to send the origonal to a speedo shop a run a diagnostic test on it. Cruise works fine also. Any other suggestions would be great Thanks. Mark , Syracuse New York