I have a 85 Blazer full size and I am getting some weird Alternator problems. It charges then stops then charges. This is a new alternator the one before this wouldn't charge more than 12v and the one before that would charge and then stop like the current one. I have tested the previous ones at AutoZone and they were bad. This one was tested before I took possession of it and passed but is now doing this. When I test it, it will either charge with 50 amps and nothing wrong or will not charge and they will say its disconnected or something. I have replaced that plug that goes in it too. I am wondering if I have been getting some bad parts or is there something else that I am missing?
Thanks in advance for your help. I am glad that these are easy to change or this could be a lot worse I think?