No heat?

[Adam240sx]

So winter is shortly around the corner and I figured I should get on this while it's still warm out. Anyway ever since I got my current s13 240sx it hasn't had heat. I have a/c that works, just needs to be charged. I have a/c but no heat. Do the a/c and heating system tie in together? I've looked this up on here before but can't seem to find much help. I'm hoping it's not my heater core. Is it a pita to replace the heater core? The dash would most likely come out because of it's location, correct? I've already switched dashes myself, so dash removal is not a concern. The heating system ties into the radiator and coolant from what I've read. Is there a certain fuse for the heating system? If anyone could share any information to help me I would be so grateful.

God Bless

[Adam240sx]

I thought people would be more helpful but I guess not!! wow thanks...