Topic: charging issue

[82toy]

ive got an 82 p/u and the when i start the truck the charging system will not kick on until i rev the engine to about 4000 RPM. any one got any ideas. ive checked the wiring and grounds and they all look good especially for being 30 years old. any help would be greatly appeciated

[Cheesemaker]

Sounds like time to do a GM 1 wire.   

I would lean towards the regulator going out. 

[82toy [OP]]

even after i replaced both the alt and reg it still does it

[Cheesemaker]

I'd start checking all the wires.  Look for something loose or corroded.  My BIL had a 87 that would intermittently charge.  Come to find out, there was a loose wire going to the carb that was causing the issue.