u/Festivefire

I'm trying to use RCS thrusters to stabilize an orbital stage, but I can't get them to fire no matter what I do.

Whether they're standard helium thrusters or using some other propellant, Kerbal engineer shows they have fuel and I have RCS delta V, but I can't use them in flight. I've made sure I have high pressure tanks for the RCS propellant as well. I've tried adding extra Helium to pressurize the system as well, still no luck.

If anybody knows what I'm doing wrong here, any help would be appreciated.

EDIT: RESOLVED. Turns out the interstage I was using for fairings didn't allow crossfeed. I fixed it by switching to a different interstage.