Something in the charging system of my truck isn't working... any ideas?

have you gotten a repair manual?that might be a gr8 place to start.im not sure of that machine,but if it uses the same system as the 88 and it probably does,the pigtail is prone to fire,the one that plugs into the alt,it gets intermittent contact.usually comes in a quality alternator box set.the old one is cut off,the new one is installed with solder or crimping and shrinkwrap.