I had to run some errands the other day and drove into a rain storm, already had the headlights on as a habit , well after turning on the wipers and the defrost so I could kinda see out the front windshield, seems like the wipers were really slow. After the rain slowed down some I could crack a window and not drown so I turned the blower off and the wipers finally started moving like I thought they should. So is this an alt problem or power problem? I will assume that I have a standard 90 amp alt on my 87 chief but I have been known to be wrong before.... just ask my wife she will tell you so! So what do I need to do or just learn to live with it and keep on driving? Thanks for the advice TN_Medic