I swapped out my battery yesterday, car fired up no problem. Now the digital speedometer doesn't show, but the dash brake light, the battery light and the seatbelt light all stay on. My ebrake is not on, my seatbelt is, the battery is brand new. Any clues?
91 240sx Changed Battery, Now speedometer doesn't show on 1991 Nissan 240SX
Sorry for the late response. This sounds like the diodes in your alternator have failed. Check all connections at the alternator especially the voltage regulator plug. If all sevure your alternator probably needs to be replaced.