My 2001 Ranger with 4.0 L speedometer and tach stopped working, the battery then went dead while driving. I had the battery and alt checked and the alt output was weak, so I put on a new one. This didn't help. The speedometer and tach still do not work nor does the voltage meter. A couple of things that started happening a day before this: the airbag light started flashing occasionally and the theft system went off while parked.
Could this be a pcm problem? Would the pcm keep the alt from charging the battery?