I tried charging my ac today.

When checking the pressure it was cycling from 15 to 35 psi. The clutch was engaging and disengaging every 5 secs or so. Is this because it's really low on ac charge or is something serious wrong with it?

S70 GLT

 

Yes it's cycling because it's too low. So try to fill it. If your using a can the output pressure isn't high enough to burst lines so don't be worried about over filling either