MY 1990 DODGE DYNASTY WONT KEEP A CHARGE WE HAVE HAD THE ALTERNATOR CHECKED ITS GOOD AND SO IS THE BATTERY ANY THER REASONS IT WONT KEEP A CHARGE IT WILL DRIVE FOR ABOUT 30 MIN AN THEN DRAINS THE BATTERY

It has to be a problem with the battery. Since it is good, you need to check the wire ends that connect to the battery post. Make sure they are not loose and they are connected good. Make sure they are cleaned. You need to check all wires in the charging system. Make sure the alternator wires are correct and getting 12V of power to it. You can check the wires with a volt meter. The wires should carry 12V. Since both parts are good, it has to be in the wires, the charging system.

You need to find out what the battery drain is as it is running, a competent auto electrician can do that. I am assuming that the battery capacity has been checked as ok and if it is there must be a VERY VERY high battery drain as it is running, something must be getting very warm. I think either the battery is not draining or your previous check on the battery alternator have not been done properly. Change the battery and see what happens.
I hope I have been of help but please do not hesitate to ask if you have any further questions.
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