71 blazer heater/defrost box

[chevyguy_72]

Anyone seen a box like this? The left side looks different than any I have seen before...

[hemi43]

Looks like "heater delete" option.

[chevyguy_72]

Originally Posted by hemi43

Looks like "heater delete" option.

There is a flapper inside of that box and a slot cut in the bottom and each corner... You can kinda see them in the pics...

[hemi43]

Originally Posted by chevyguy_72

There is a flapper inside of that box and a slot cut in the bottom and each corner... You can kinda see them in the pics...

Yeah, but there's no fan. Even with heater delete, laws back then still required some sort of defrost. Even vehicles with heater delete, will still have a heater core. Not sure how GM did it, but I'm familiar with Mopars of the 60's

[chevyguy_72]

Originally Posted by hemi43

Yeah, but there's no fan. Even with heater delete, laws back then still required some sort of defrost. Even vehicles with heater delete, will still have a heater core. Not sure how GM did it, but I'm familiar with Mopars of the 60's

Theres not a fan under there either way...
The fan is on the firewall next to the heater core...
The only thing under there is the box with all the flappers.

[GMC-YA68]

Yea, but if you put a fan on the firewall, then turned it on...where is it going to blow? - not in that box because it's not connected to it in any way.

[chevyguy_72]

Originally Posted by GMC-YA68

Yea, but if you put a fan on the firewall, then turned it on...where is it going to blow? - not in that box because it's not connected to it in any way.

Not sure what you mean here?
This has the same engine bay heater core/fan unit... i was just showing the first pic to show that its a non AC unit...
The stock located fan will blow through the heater core and into the cab portion of the heater box... my only question is the reason for the different shaped unit that disperses the heater and defrost.

[hemi43]

Originally Posted by chevyguy_72

my only question is the reason for the different shaped unit that disperses the heater and defrost.

Like I mentioned before, most likely it had "heater delete" option.

[chevyguy_72]

Originally Posted by hemi43

Like I mentioned before, most likely it had "heater delete" option.

Sorry but that doesn't make sense to me since it actually has heater ports on the bottom and sides? A delete to me would be no heater at all... maybe just a defrost unit... this still has both and a flapper inside to control between them with all 3 wires and the same controls as the other unit...

[cleszkie]

Whatever you have there apparently did not come with that truck because I can see the mounting holes where the original box was mounted. Are there provisions for a heater core inside the box, or any sign of openings that heater hose could have been routed into? Otherwise that box is pretty much worthless as a defrost without a fan, and worthless as a heater without a fan and source of heat.