Honda Repair: honda prelude 1994, speedometer gear, speedometer cable

Question
I have an auto 2000cc 1994 prelude with a speedo problem that has just started.  When switched off the speedo reads 0 but when the ignition is on it goes to 20 mph and tends to stay there, when driving it may move up slightly but does not read the correct speed.  the odometer works fine.  Is this an easy fix?

Answer
Will:
If you have a cable operated speedometer check the speedometer cable to make sure it is seated properly, make sure the cable is not broken and check the speedometer gear condition. If it is electronically operated, check the speed sensor pickup, check the wiring to the speed sensor. I would say this is not too complicated to fix.
Good luck.
Bill