in my mx3 i can not get my alt. to charge my bat can anyone help is this a common problem.

Hope I can help! Have you checked with the dealer to see if there are any outstanding recalls on your car? The used to be one for a problem with the alternator in V6 models in the earlier years, for a corrosion problem. Otherwise likely an internal problem in the alternator. Have you changed the alternator yet? Let me know how you make out!