I have an rog strix g16 whenever i plug it in the system fan goes to 3000 rpm

[Hemo3579]

my rog strix g16 when unplugged the system fan sits at 0 rpm

when plugged in reaches 3000 rpm

does this signify a faulty charger overheating the battery?

im using the charger that come in the box with no adapter, just the charger

[Frinik22]

Have you tried adjusting the fan speed in Armoury Crate? It may just be that your laptop was programmed like that by default at the factory by Asus?

[eXplode]

Did you hear the fans working when you unplug the charger this can be a software bug 

Another thing you can do ehen you unplug you laptop is to change the gaming profiles and then you can try to hear and see if they work 

Another thing you can try is unplug the charger and then create a custom fan profile (check this post its show how to make it) and you will see did they work or not 

https://rog-forum.asus.com/t5/rog-strix-series/temperatures-on-rog-strix-g16-g614ji-during-intense-g...

If they dont work do a clean uninstall of the program whit Armory Crate uninstall tool and istall it again 

Also can you check on what temperature the laptop work when you unpluged it from the charger and what profile you use

[C-V-N]

You could try the software called G-helper it's a light weight tool for ASUS laptops.  (it doesn't have all the bloatware)