Hi I am new here so hopefully this is a good spot for this question. I'm in the midst of a 4.3 5.7 swap in a 2002 blazer 5sp 4x4. I decided to go no ac. I ripped off the evap coil and blower motor housing. I want to fabricate a new blower motor housing as I have the skills and access to equipment to do so. My question is do I have to duct the housing over to the other hole in the firewall where the evap coil was or can I blank that one off?

Down and to the right of the blower motor hole is a damper. Do i need thst with no ac?

 

What year Blazer? On my 1999, I'm pretty sure the blower motor with the squirrel cage that goes into the circular hole blows air through your old evaporator into that vertical, rectangular hole in the firewall.

 

Air intakes through the circular hole into the blower motor. Then it ducts through the evaporator housing, down through that rectangular opening, through the heater core, then through the dash ducting and vents. To delete the AC but keep heat, you need to duct the air to the rectangular opening still. Some S10's came without AC, you may be able to find one in a junk yard and salvage the box from it to use. But if you're not looking to retain AC or heat, just block off both holes and don't worry about it

 

thank you! just what i needed to know. i need to keep heat in case i try to drive it in winter here in ohio. i will see what the stock piece looks like but wont mind fabricating my own to maximize the space.