First just check the obvious things.
1) Your battery terminals are all clean and tight.
2) Your block ground (From the battery to the front of engine) is clean and tight.
3) Your plug into your alt is in correctly, tight, and right. So is the charge cable.
4) The plug going into the voltage regulator is on correctly and making contact on all pins. (It is not easy to get these off or put back on.)
If yes to all the above then here is a long shot but mabye your issue. One of the wires that grounds your regulator goes into a spliced connection, and mabye another sliced connector, before getting grounded to the truck. (This is all on your passenger fender well.)
When I did the starter soleniod (Gave out after my compression test last year.) I moved/bumped the wiring around in that area. Then my alternator light came on after getting the solenoid in. I followed the wires out of the regulator and low and behold I beleive it was the black one, went from the regulator plug, to a slide connector, and I want to say another slide connector, then screwed into the fender well. Turns out these connections were corroded. Just moving that connector around moved it over inside to a spot that was corroded and caused a lack of ground. I cleaned up the connectors, plugged back in and whammy it all worked. So just check for that.
Another possibility is the wire from your alt to the starter solenoid is the charge wire. Not any old wire, it is a fusible link wire. No fuse as you know it, rather too many amps and it burns inside and stops the connection. (But you cannot see it burned.) Then no power from the alternator to the positive side of the electrical system. So you may want to OHM check that wire.
Then if not like mentioned above could be one or both parts are bad. Never assume new parts work, often they do not. Most auto parts stores can test both parts. Don't be bashful to take the parts to a differnet store and ask them to test to confirm they are working.
Some videos that might give you some ideas
xc_hide_links_from_guests_guests_error_hide_media
xc_hide_links_from_guests_guests_error_hide_media
Post some pics and let us know what you found!
