on a Chevy 2000 Blazer, is there a fuse that can cause the heater to not blow hot air?

Is there no hot air discharge or is the discharge okay buy not hot enough? It makes a big difference. BUT, that said, the blower "module" on many GMS of that era have problems with the HIGH blower position not working. All the other speeds (3) may work just fine but then in HIGH the blower shuts off. It's usually the heater "module" (which isn't really a module at at ::: no electronics of mechanical parts as it were) that burns out the full voltage signal to the blower motor. The replacement of this unit require a 5.5mm deep 1/4" drive socket. The socket is rather hard to find in most parts stores that cater to non-professionals. If the blower is the culprit b/o the "module" I can help.