John Burns Posted February 18 Share Posted February 18 My car had factory AC and a long time ago I removed the evaporator box and installed an AC delete plate in the engine compartment. This kept the heat, but I still have all the controls under the dash that are operated by a spaghetti of vacuum tubes. I picked up a non-AC control panel, but there is no way to attach this to the old AC stuff under the dash. And yes, I still want heat! Has anyone ever removed this vacuum spaghetti and the AC box under the dash? It still kinda works, but it is worn out and I just realized it is creating a vacuum leak. Does anyone have a non-AC box that goes under the dash? It appears it is operated with 3 cables. Thanks! Quote Link to comment Share on other sites More sharing options...
Dtret Posted February 19 Share Posted February 19 Maybe. I’ll look tomorrow. 1 Quote Link to comment Share on other sites More sharing options...
Dtret Posted February 19 Share Posted February 19 All the ones I have are for a/c. Sorry. 1 Quote Link to comment Share on other sites More sharing options...
MCfan Posted February 20 Share Posted February 20 Hi, John, My '70 was built in Baltimore with a heater only system. When I acquired it in 2010, I immediately removed the factory heater box and controls and installed a Classic Auto Air system. Since I seldom throw anything away (thinking myself or someone else may have a need for it someday 😄), I put all of the factory parts in a big box and put it into storage. I has now survived three different storage system moves but I believe it is all intact. If you are seriously interested, I can pull it out of storage and take some photos for you of what I have. At this point, I don't ever plan on returning my car to its original low-option configuration so I can make these parts available. I would think a salvage yard might be another good source for you but it would require a good deal of work to remove everything from a junked Monte. Just let me know. Thanks. 6 Quote Link to comment Share on other sites More sharing options...
stangeba Posted February 20 Share Posted February 20 I am looking for a picture of the first generation Monte firewall and how different it is with vs without A/C. All I have so far is my 71, NO A/C firewall, from the inside and outside, when I replaced the heater core that was leaking. I think I remember it being online, still looking. 3 Quote Link to comment Share on other sites More sharing options...
Dtret Posted February 20 Share Posted February 20 I was driving and thinking about the firewall difference. Here’s a picture of my 70 with AC 2 Quote Link to comment Share on other sites More sharing options...
John Burns Posted February 20 Author Share Posted February 20 9 hours ago, MCfan said: Hi, John, My '70 was built in Baltimore with a heater only system. When I acquired it in 2010, I immediately removed the factory heater box and controls and installed a Classic Auto Air system. Since I seldom throw anything away (thinking myself or someone else may have a need for it someday 😄), I put all of the factory parts in a big box and put it into storage. I has now survived three different storage system moves but I believe it is all intact. If you are seriously interested, I can pull it out of storage and take some photos for you of what I have. At this point, I don't ever plan on returning my car to its original low-option configuration so I can make these parts available. I would think a salvage yard might be another good source for you but it would require a good deal of work to remove everything from a junked Monte. Just let me know. Thanks. Hi Dennis, Thank you very much for the offer! I am going to attempt to adapt the AC heater box to the non-heater controls. That might sound nuts, but I think it might actually be easier than swapping in a factory heater box. I pulled the ac heater box already, removed the diaphragms, and have figured out how I want the various doors to operate mechanically (stay tuned). BUT, for documentation's sake, it would be really cool to see all of the non-AC parts. AC cars are well documented, but I haven't found any good info on a non-ac car. And I have searched many A-body forums! Some things I'd love to know about your car: Where is (was) the "heater resistor" mounted? Where do (did) all three of the control cables go? (Especially the one controlled by the OFF - AIR lever.) What do the factory fresh-air ducts that come from the cowl look like? Did you keep them? There are "fresh air doors" on either side that operate from pulls on the kick plate. I'd love to see a photo of this. One interesting thing I have learned: the non-ac blower wiring and connectors are in every car. If ac was installed at the factory, they installed an ac harness and simply tucked the non-ac wiring and connectors out of the way. Again- I very much appreciate the offer. And if I crash and burn on my current plan, I might hit you up for those parts! Thanks John Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted February 20 Share Posted February 20 I belive they make an ac delet plate, I saw it somewhere but don't remember where. Quote Link to comment Share on other sites More sharing options...
Dtret Posted February 20 Share Posted February 20 8 minutes ago, cny first gen 71 said: I belive they make an ac delet plate, I saw it somewhere but don't remember where. They do. Quote Link to comment Share on other sites More sharing options...
Dtret Posted February 20 Share Posted February 20 32 minutes ago, John Burns said: Hi Dennis, Thank you very much for the offer! I am going to attempt to adapt the AC heater box to the non-heater controls. That might sound nuts, but I think it might actually be easier than swapping in a factory heater box. I pulled the ac heater box already, removed the diaphragms, and have figured out how I want the various doors to operate mechanically (stay tuned). BUT, for documentation's sake, it would be really cool to see all of the non-AC parts. AC cars are well documented, but I haven't found any good info on a non-ac car. And I have searched many A-body forums! Some things I'd love to know about your car: Where is (was) the "heater resistor" mounted? Where do (did) all three of the control cables go? (Especially the one controlled by the OFF - AIR lever.) What do the factory fresh-air ducts that come from the cowl look like? Did you keep them? There are "fresh air doors" on either side that operate from pulls on the kick plate. I'd love to see a photo of this. One interesting thing I have learned: the non-ac blower wiring and connectors are in every car. If ac was installed at the factory, they installed an ac harness and simply tucked the non-ac wiring and connectors out of the way. Again- I very much appreciate the offer. And if I crash and burn on my current plan, I might hit you up for those parts! Thanks John Man was I confused. ( I know that doesn’t take much) I post a pic of an AC firewall and get that response. lol. 1 Quote Link to comment Share on other sites More sharing options...
stangeba Posted February 20 Share Posted February 20 I just did a search and found this: https://www.luttyschevy.com/i-20829331-firewall-ac-delete-cover.html 1 Quote Link to comment Share on other sites More sharing options...
MCfan Posted February 21 Share Posted February 21 5 hours ago, John Burns said: Hi Dennis, Thank you very much for the offer! I am going to attempt to adapt the AC heater box to the non-heater controls. That might sound nuts, but I think it might actually be easier than swapping in a factory heater box. I pulled the ac heater box already, removed the diaphragms, and have figured out how I want the various doors to operate mechanically (stay tuned). John, I'm not sure I can help you much with your questions. The A/C and non-A/C systems on first gen Montes are worlds apart in size, complexity, controls and operation. Maybe you have figured out a way to replace the vacuum operated functions with the three levers and cables of a non-A/C panel but I but I am highly skeptical. The three manual levers on the non-A/C panel control Fresh Air, Heater temperature and windshield defrost. As you know, with an A/C box all of that stuff is controlled by the various positions on the top lever on an A/C panel by using vacuum circuits. IMO, you would be much better off just using the right hand side of your A/C panel after installing an A/C delete plate on your firewall. I had to remove the A/C box from my '70 SS (to "de-mouse" it) so I know how complex it is and how it fundamentally switches between heating and cooling. Since the sole function of the lower lever and cable on the A/C system (see photos) was to manually flip the door that connected the air box to the A/C evaporator on the engine side of the firewall (simultaneously blocking the heater portion), you can just leave it in the far right position. I can't imagine that deactivating the A/C portion of your system by removing the engine compartment components would also deactivate the heating portion including its vacuum operation. If you really want a heater-only control panel, I'm pretty sure you are going to need an original heater-only box plus an A/C delete plate. In addition, your A/C car does not have the Astro Ventilation system that a non-A/C car has (i.e. no knobs to operate fresh air inputs on the dash ends or in the kick panels. If you want to have an operational Astro Ventilation system, I suggest you find a non-A/C car in a salvage yard and strip out the entire system including kick panels and dash vents. Sorry to be a pessimist but I would never attempt what you are trying/hoping to do! Quote Link to comment Share on other sites More sharing options...
John Burns Posted February 21 Author Share Posted February 21 14 hours ago, Dtret said: Man was I confused. ( I know that doesn’t take much) I post a pic of an AC firewall and get that response. lol. Hi Dennis! I was replying to MCfan- he is Dennis too! Quote Link to comment Share on other sites More sharing options...
John Burns Posted February 21 Author Share Posted February 21 9 hours ago, MCfan said: John, I'm not sure I can help you much with your questions. The A/C and non-A/C systems on first gen Montes are worlds apart in size, complexity, controls and operation. Maybe you have figured out a way to replace the vacuum operated functions with the three levers and cables of a non-A/C panel but I but I am highly skeptical. The three manual levers on the non-A/C panel control Fresh Air, Heater temperature and windshield defrost. As you know, with an A/C box all of that stuff is controlled by the various positions on the top lever on an A/C panel by using vacuum circuits. IMO, you would be much better off just using the right hand side of your A/C panel after installing an A/C delete plate on your firewall. I had to remove the A/C box from my '70 SS (to "de-mouse" it) so I know how complex it is and how it fundamentally switches between heating and cooling. Since the sole function of the lower lever and cable on the A/C system (see photos) was to manually flip the door that connected the air box to the A/C evaporator on the engine side of the firewall (simultaneously blocking the heater portion), you can just leave it in the far right position. I can't imagine that deactivating the A/C portion of your system by removing the engine compartment components would also deactivate the heating portion including its vacuum operation. If you really want a heater-only control panel, I'm pretty sure you are going to need an original heater-only box plus an A/C delete plate. In addition, your A/C car does not have the Astro Ventilation system that a non-A/C car has (i.e. no knobs to operate fresh air inputs on the dash ends or in the kick panels. If you want to have an operational Astro Ventilation system, I suggest you find a non-A/C car in a salvage yard and strip out the entire system including kick panels and dash vents. Sorry to be a pessimist but I would never attempt what you are trying/hoping to do! Hi Dennis B, I thought you said your car was born with "heater only"! It appears it was an AC car, but maybe someone had removed the evaporator (the big box in the engine compartment) before you got it? I want to do this conversion because the vacuum hose mess under the dash is leaky, and I don't want the factory AC control panel if I don't have AC! I already have the AC delete plate on the firewall inside the engine compartment. Now I am removing all of the vacuum operated stuff under the dash. I have the heater only control panel already and I'm pretty sure I can adapt the cables to operate the doors in the AC box (like I said: stay tuned!). As for the Astro Ventilation, repop kick plates with the knobs / cables are available. I have removed my AC kick plates (passenger side was a vacuum operated vent and drive side has a bolt-on block off plate). I'll post pictures of this whole craziness when I am done! John Quote Link to comment Share on other sites More sharing options...
John Burns Posted February 21 Author Share Posted February 21 23 hours ago, stangeba said: I am looking for a picture of the first generation Monte firewall and how different it is with vs without A/C. All I have so far is my 71, NO A/C firewall, from the inside and outside, when I replaced the heater core that was leaking. I think I remember it being online, still looking. I would love to see a whole factory "heater only" set up. I couldn't find any photos online. I can only find the assembly manual photos, but they are missing tons of detail. Quote Link to comment Share on other sites More sharing options...
MCfan Posted February 21 Share Posted February 21 18 minutes ago, John Burns said: Hi Dennis B, I thought you said your car was born with "heater only"! John, I currently own a factory heater only '70 that I have installed Classic Auto Air in (as shown in the photos below). As I said in my prior post, I had to remove the A/C box from a '70 SS that I also owed for eight years. Three of the four pictures I sent earlier were of that car, not the '70 non-A/C car I still own and drive in FL. Sorry for the confusion. Good luck with your project. Based on all you have already done, it sounds like there is probably no going back now! 😄 1 Quote Link to comment Share on other sites More sharing options...
MC1of80 Posted February 21 Share Posted February 21 Here is a pic of the firewall for a non-A/C car and the inner and outer heater only set up. 3 Quote Link to comment Share on other sites More sharing options...
Dtret Posted February 21 Share Posted February 21 1 hour ago, John Burns said: Hi Dennis! I was replying to MCfan- he is Dennis too! I realized that. lol. Quote Link to comment Share on other sites More sharing options...
John Burns Posted February 21 Author Share Posted February 21 1 hour ago, MC1of80 said: Here is a pic of the firewall for a non-A/C car and the inner and outer heater only set up. Very cool- that heater box is what I was after. Do you have any photos of the fresh air vents - or the holes for those vents? From what I understand, they are supposed to be under the dash, at the top of the fire wall. One hole on each side that goes into the cowl. At this point, I don't think I'm going to get that ambitious to add them, but I would love to actually see them- I can't find any photos online. Thanks! Quote Link to comment Share on other sites More sharing options...
stangeba Posted February 21 Share Posted February 21 If this helps any: Left NO A/C, Right With A/C 2 Quote Link to comment Share on other sites More sharing options...
stangeba Posted February 21 Share Posted February 21 I believe I saw something about how the A/C version does NOT have fresh outside air for the 2 L&R dash vent in the dash or floor vents. I remember I have the steel plates that fill this hole one each side. I remember now why I never converted my NON A/C to A/C all those years ago, TOO MUCH WORK! The picture on the bottom is after I removed the KICK panel to replace the chrome vent cables. The chrome was not the best but after about 3 years all 4 cables plastic part BROKE and now don't work. I think I kept the original ones!! 2 Quote Link to comment Share on other sites More sharing options...
John Burns Posted February 22 Author Share Posted February 22 15 hours ago, stangeba said: I believe I saw something about how the A/C version does NOT have fresh outside air for the 2 L&R dash vent in the dash or floor vents. I remember I have the steel plates that fill this hole one each side. I remember now why I never converted my NON A/C to A/C all those years ago, TOO MUCH WORK! The picture on the bottom is after I removed the KICK panel to replace the chrome vent cables. The chrome was not the best but after about 3 years all 4 cables plastic part BROKE and now don't work. I think I kept the original ones!! You are correct- the A/C version does NOT have fresh outside air for the 2 L&R vents in the dash, but behind the passenger side kick plate, there is a vacuum actuated fresh air duct. And I agree- trying to put factory air in a non-air car would be way too much work! The firewall rework alone would be brutal. And your second photo is the hen's tooth picture I have been looking for! Now I see that round duct isn't in the firewall- it is off to the side and it goes to the cowl (one one the driver side too). I'm on the fence about trying to add these- it would be a ton of work, but also nice to have a fresh air option other than the kickplate vents. Not sure if the climb is worth the view! Thanks!! 2 Quote Link to comment Share on other sites More sharing options...
MCfan Posted February 23 Share Posted February 23 On 2/21/2024 at 4:46 PM, stangeba said: I believe I saw something about how the A/C version does NOT have fresh outside air for the 2 L&R dash vent in the dash or floor vents. I remember I have the steel plates that fill this hole one each side. I remember now why I never converted my NON A/C to A/C all those years ago, TOO MUCH WORK! The picture on the bottom is after I removed the KICK panel to replace the chrome vent cables. The chrome was not the best but after about 3 years all 4 cables plastic part BROKE and now don't work. I think I kept the original ones!! Bruce, you possibly want to keep your '71 all original but if you really want to add A/C, I suggest you give a hard look at the Classic Auto Air system for the '71 Chevelle. If you contact their service/support reps and tell them it is for a Monte Carlo, they will ship the kit with extra long hoses to accommodate the stretched front end. That kit is very straightforward to install (some but not too much work), takes lesss room in the engine compartment and preserves the function of your lower (kick panel) astro vents. You used to be able to get the manual 3 lever/cable control system (see photo) but they may have moved to total digital by now. 2 Quote Link to comment Share on other sites More sharing options...
stangeba Posted February 23 Share Posted February 23 Dennis, thanks but at this point I have decided to leave it stock and (almost) as it was when I ordered it. My wife and I drive it about 1,000 miles each summer on nice days and the Woodward Dream Cruise. 3 Quote Link to comment Share on other sites More sharing options...
John Burns Posted February 26 Author Share Posted February 26 I got side tracked but I hope to finish this modification today or tomorrow! I got the blower working using the AC wiring harness and AC resistor. My wiring diagram show 2 types of AC systems called "Comfortron" and "Four-Season". I searched and only found 1 reference to "Four-Season" and none for "Comfortron". Did these Montes ever come with the "Comfortron"? I'll post pix of what I'm doing if anyone is interested. Quote Link to comment Share on other sites More sharing options...
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