94 Altima Speedometer trouble

I have a 94 Altima GXE the speedometerhas stopped working but all the other gauges are fine. The local dealership tells me its the speedometer head thats bad but I have installed two new ones and nonething. I have even changed the speed sensor. Is there anyone That can help me. I may also be reached at [email protected]. Please put
"speedometer trouble" in subject line.

my GLE Altima 93's speedometer has stopped working. Other guage on dashboard work fine. What should i do?
plz help