hey guys, i have a 1991 z28 with a 305 auto 700r4 and the speedometer doesn't work everything else works odometer, trip, oil pressure ect...i tried unplugging the vss to see if the SES would come on and it didn't so i thought ok i'll try unplugging something else so i did and the SES didn't come on again, the thing is the car runs fine so i know it's not a faulty computer, im just wondering if you guys could help me out with these two qestions....does the speedometer have a ground wire and if so where is it located?

 

I too am having speedometer problems with the same year vehicle , mines a firebird with the 120 MPH speedo. I took apart the cluster and the "screws" that hold in the circuit board. I think its my circuit board thats gone bad.

 

i dunno but check out the connection to the transmisson. unscrew it and check the end of it. i have an 84, Z28 that im swaping the 305 with a 350.. and my cable was bad. so i dunno if there that same but i would check that..

 

no there not the same mine is all electronic, and i did check the vss on the tranny, but doesn't the vss also run the trip and odometer?, because both of those work.