hello!
I have an '84 6.2 C20, and the batteries won't charge. I have replaced the alternator twice in the past 2 months, the batteries test good at Autozone. 2 days ago I ran the wire that connects to the bolt on terminal directly to the battery rather than running it to the junction block on the firewall, and yet it still won't charge...
Any help would be greatly appreciated.

 

I think you take volt meter and start at back alternator and work you way back to don't get readying will tell where the problem at

 

You mean check the voltage of the wires coming from the plug on top of the alternator?