HVAC problem with my 03 Caravan

[Snapdragon]

Hi everyone,
I have recently faced a problem with my 03 Caravan's HVAC. It operates (I as long as I change temperature, it works okay). Though, the air won't blow... So I wanted to ask you folks on what do I do to troubleshoot the problem and possible find what exactly failed. I have checked the condition of the HVAC hoses already, as well as the small valve that's in there, yet this part is fine, nothing closes the air flow from inside (at least, it's not about the hoses). What is to be checked next, folks?
 

[Snapdragon]

Wanted to share with you folks the solution I found. There appears to be a realy (HVAC relay) that operates the system. In my case, I discovered the relay failure by checking the error codes with that OBDII tool. So I grabbed the new one (https://www.carid.com/hvac-relays/), and hope that the replacement will do that.

[Drew]

A friend's 99 Durango did a similar thing with the rear heat and a/c. Found out there is a fuse box located in the steering column with 4 fuses to operate the rear controls and fan. This box is in no manual.