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I'm seeing in order to keep the heat/defrost you need to cut open the whole box in the firewall and create some passage when deleting the A/C. Why is this?
My plan is to remove the condenser and compressor as well as the lines going to the box inside the engine bay (and cap them off). I noticed some posts that defrost utilizes the A/C compressor to remove moisture/humidity from the air before coming out of the dash defrost vent.
I suppose I could pull the AC compressor fuse and run the defrost to see what happens...
If I really need to get into the heat box in the firewall to modify it, then that may deter me from doing all this...I don't want this to snowball LOL.
Plenty of vehicles on the road with only heat. Yes on cars with A/C the compressor runs to help out in defrost, but like I said, many many cars with heat only so it's not a must. You need modify the box so air can get into the heater core. In stock configuration the air flows over the condenser first, then the heater core when heat is selected. Obviously when AC is selected the the blend doors keep the air from hitting the heater core. Because of this, when you remove the out side box, you have to give the air a place to flow from the blower motor to the heater core. It's hard to explain but once you get the outside box outta the way you'll see. I did away with the AC but kept the heater core for now in my SBC swaped 95. I'll see if I can find some pictures I took when I was doing this project last year. You have any links or pictures you've found in searching? I didn't do any research, just kind of went for it haha.
I did come across a bunch of pictures. This one puts an image to your explanation. The area with the bondo is the modified section that was cut and fixed.
Maybe when a new motor goes in I will go nuts with it. Until then, I'll plan to simply remove the compressor, condenser up front and all the lines. I'll plug the holes going to the heater box for now.
AC has never been very useful in my car and is now holding back some fun modifications.
I have all my A/C stuff deleted but was under the impression I still needed the coolant lines going to the firewall box for the heater to work. I've had no issues just using heat to defrost the windows and I drive my car well into early December (depending on when the first snowfall is here in the north east)
I did come across a bunch of pictures. This one puts an image to your explanation. The area with the bondo is the modified section that was cut and fixed.
Maybe when a new motor goes in I will go nuts with it. Until then, I'll plan to simply remove the compressor, condenser up front and all the lines. I'll plug the holes going to the heater box for now.
AC has never been very useful in my car and is now holding back some fun modifications.
That is essentialy exactly what I did. I just cut out enough of the area to allow air to head "that way" and it blows through the heater core, which is located in the inside half the heater box housing. You'll need to buy or make a AC firewall delete plate though.
Originally Posted by hokeplaya05
following.....
I have all my A/C stuff deleted but was under the impression I still needed the coolant lines going to the firewall box for the heater to work. I've had no issues just using heat to defrost the windows and I drive my car well into early December (depending on when the first snowfall is here in the north east)
Yup, you need to keep the heater core inside the car, and then the two coolant lines going to it.
Not the best pictures, but here's mine. I don't think I even used bondo or anything fancy. Just gorilla tape because I wanted to see if it even worked before I invested more into it. I haven't hooked up my hoses to it because I'm working out exhaust and a hood, but, air does flow through to the defrost vent.
I have all my A/C stuff deleted but was under the impression I still needed the coolant lines going to the firewall box for the heater to work. I've had no issues just using heat to defrost the windows and I drive my car well into early December (depending on when the first snowfall is here in the north east)
You need engine coolant lines running to the metal pipes (which is the heater core) coming through the firewall. Otherwise you won't get warm air.
I just removed the A/C compressor fuse and tried defrost. Turning on the defrost selection and turning temp **** cold, it gets colder. Turn temp **** full hot, it gets warmer without the compressor running (due to removed fuse). I think I read the A/C components are used to remove moisture/humidity from the air before coming out the vents for defrost.
So I think this answers my question. You can remove the compressor, the front condenser and the A/C lines running to the HVAC box inside the engine bay and plug the holes in the HVAC box.
A/C is just to remove moisture from the air. Back when I daily drove mine, defrost worked just fine without A/C.
You only need to cut that channel in the box if you're hacking up the box to put in a delete panel to make more room in the engine bay. If you're leaving the evaporator core in the box, there's no need for it.
A/C has no bearing on temperature control. The temp **** on the HVAC controls is just a cable-driven actuator for the box's blender door, which allows either evaporator or heater core temperature to flow through the vents.
I did come across a bunch of pictures. This one puts an image to your explanation. The area with the bondo is the modified section that was cut and fixed.
Maybe when a new motor goes in I will go nuts with it. Until then, I'll plan to simply remove the compressor, condenser up front and all the lines. I'll plug the holes going to the heater box for now.
AC has never been very useful in my car and is now holding back some fun modifications.
So the box that protrudes out into the engine bay is just held in by bolts? I thought it was all one and it had to come out with the under the dash components?
If i can just remove the box my bolts and put a plate on it to keep the heat, im gonna go do it now lol.
I'm not sure how half of the HVAC box is held together or fastened to the firewall, but I find it hard to believe it can be done with the engine in there. Therefore, I'm not messing with it to go that far.
When an engine swap occurs I will do this.
IF it can be done with the engine in the car...well then I may have to get creative
I'm not sure how half of the HVAC box is held together or fastened to the firewall, but I find it hard to believe it can be done with the engine in there. Therefore, I'm not messing with it to go that far.
When an engine swap occurs I will do this.
IF it can be done with the engine in the car...well then I may have to get creative
The engine in the picture I quoted is still in the car, the coil packs and cover is removed but probly could be done with just the coil packs off. Took a look at it and it looks easy to do with a rotory tool and a small wheel.
The engine in the picture I quoted is still in the car, the coil packs and cover is removed but probly could be done with just the coil packs off. Took a look at it and it looks easy to do with a rotory tool and a small wheel.
On mine, my engine was out...but it can still be done with it in the car, if you are not concerned with it ever going back in the car it's a lot easier haha. Technically it bolts together from the out side and inside, so to do it correct, you need to pull the dash and such to remove both halves, to remove the engine bay side, then modify the inside portion and bolt it back in with your block off plate. I removed what I could from out side, and using a few different air cut off wheels, grinders, and body saws I cut it out in pieces and made it flush. Then used poster board, made a template, cut it out and used some sealer around the edge and used self tappers around the edge since the inside box is still there and I couldn't use that hardware/open bolt holes like you would if you deleted all the HVAC. Not hard, just time consuming and makes a hell of a fiberglass mess
Yup, you need to keep the heater core inside the car, and then the two coolant lines going to it.
Originally Posted by smitty2919
You need engine coolant lines running to the metal pipes (which is the heater core) coming through the firewall. Otherwise you won't get warm air.
okay good, that is how I have it now, just misunderstood the original post stating removing all lines to core. I am planning on pulling the motor at some point over the winter so this looks like a good task to tackle to clean up my engine bay a bit.
okay good, that is how I have it now, just misunderstood the original post stating removing all lines to core. I am planning on pulling the motor at some point over the winter so this looks like a good task to tackle to clean up my engine bay a bit.
Yup, makes so much more room in there, Headers and plug changes are a ton easier too.
If I was do it with the motor in the car I may entertain removing the PS header and spark plugs to gain more room. Remove the PCM and anything else you could.
Kick out is for the wheel to spin. It's seems others all the plate without this feature so I assume you really don't need it. But I err on the side of caution.
01-08-2018, 02:33 PM
AC delete, keep heat/defrost 
