speedomoter probs

[ant33510]

I have a mojor problem, i just bought an 91 240SX SE from a dealer " one of those off the side of the road ones" and the engine is great well maintained and everything the only prob it my speedomter does not wrk, here are the details it will come on when ya first start the car then go away, oh ya i forgot to tell ya it is digital, so i am totaly clueless on how to fix this problem before i get pulled over for speedin...

thanks,
Anthony