[davemc53]

My battery charges fine when I have the truck sitting in the driveway, but will not charge when it is going down the road. My mechanic has checked the alternator (OK) and starter (OK also). When I drive to work I have to let it sit idling for 10-15 minutes and then it is fine 8 hours later when I am ready to go home. And I have to go through the same when I get home, and it is fine the following morning. Mechanic seems to think it is the computer sending mixed messages to the alternator. I know very little about electrical systems. Please Help!!!!!!!!!!
(I have a 89 Dakota 3.9 4WD)