I have a 1997 F-150 4x4 having electrical problems , the air bag light came on won't go off ever since this happened the speedometer has a mind of it's own works when it feels like working and the truck seems to be discharging on it's own when parked. Parked it on Saturday morning came out monday to go work battery dead new battery just put it ,would not even take a boost the battery was that dead . Had it on computer the only code that showed up was bad battery not the problem new abbery . ,and when you shut off the vehicle you can a noise coming from under the dash. Lost for solutions ??????

 

You have a short somewhere which is allowing for your battery to drain and your gauge to act up.