Inner Cab Heater/AC Housing Reference Pics

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89Suburban

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I'm also thinking of adding one of these. You run your heater hose thru it. So it can shut off the flow thru your heater core in the summer time. I hate my trucks that have AC and all the heat that comes thru the ducts when the AC is off or not working. Even with the blend door to COLD, if the blend door doesn't seal 100% you still get heat thru the vents. This should keep the heater core much cooler and not have that problem so bad.
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My 84C20 is like an oven in the Summer. Although I've not checked the blend door either. And it's heater and defrost work great too.

Do you remember the part number for this?
 

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I think this is the right thread... but my heater core cracked and died this weekend. I was sitting at a light when anti-freeze steam started coming in through the vents and passenger footwell. I bypassed the heater core until I get it replaced.

I have an 84 K10 w/ AC. Which heater core should I buy? Rockauto has four different makes and cores for AC trucks: PRO, TYC, Spectra, and Vista-Pro.

Also, do I have to remove the AC Condenser and blower motor on the firewall? Where should I start dissembling to replace the heater core?
 

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Do you remember the part number for this?


I've not done this mod yet, but I sure like the idea for keeping the heater core cool when not using AC.

Having this thing set up to have the heater core circulation blocked off in the summer would be great. However, if running AC, I'd want it to go ahead and circulate and it could be wired to do so. The Heater core does add capacity to the cooling system and when the AC is running, increased capacity is a good thing. Also a good chance the cold coil in the air dizzy could actually be cooling the core too.
 

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Was it this thread or did 89S have another thread for heater core replacement. I see no pics in the first few posts of this thread anymore.

I'm begining to think 89S is deleting his pics now. :shrug: Is it time for me to get out the ban hammer Dawg??? Just be sure I have your phone # before I do. We'll have to keep in touch somehow. :rofl:
 

89Suburban

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I think this is the right thread... but my heater core cracked and died this weekend. I was sitting at a light when anti-freeze steam started coming in through the vents and passenger footwell. I bypassed the heater core until I get it replaced.

I have an 84 K10 w/ AC. Which heater core should I buy? Rockauto has four different makes and cores for AC trucks: PRO, TYC, Spectra, and Vista-Pro.

Also, do I have to remove the AC Condenser and blower motor on the firewall? Where should I start dissembling to replace the heater core?

You don't have to pull the AC condensor or the blower cover on the engine side of the firewall but you do have to unbolt them because the same bolts hold the heater box to the inside. From what I can try to remember there is 2 bolts both top and bottom and one on the side of the blower. 3 of them are actually studs with nuts holding them and can be a real bastard to remove. They usually have the seam sealer stuck on the threads along with dirt and rust. They will just spin the studs and not come off. That's when you start throwing stuff. It's not a fun task at all. I got to get the spare housing I have and try to do a write up of an easier way to replace this when I can find the time.
 

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Was it this thread or did 89S have another thread for heater core replacement. I see no pics in the first few posts of this thread anymore.

I'm begining to think 89S is deleting his pics now. :shrug: Is it time for me to get out the ban hammer Dawg??? Just be sure I have your phone # before I do. We'll have to keep in touch somehow. :rofl:

Stop accusing me of deleting pics this week you horses ass lol
 

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Anyone have the vacuum diagram. The previous owner of my truck left the vacuum ball on there but disconnected the black plastic line that runs to it from the selector switch also the the line that connects to the motor is gone. I need a diagram to check all the vacuum lines from the selector switch to every pod even the vacuum canister. Thanks!
 

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I wish someone would find one. I'm not sure of underhood, but underdash there is only 3. 2 go to the hot cold blend door and 1 goes to the defrost blend door. The lines come off the HVAC controller

But hell, don't quote me. Now I"m think it's 2 to the defrost blend door. 1 is for pulling the door closed, and another for pulling the door open. One of mine to the pull off is missing. So if I start the truck on defrost it will go to defrost, and it will pull off OK and go back to floor or vents when I hit the controller, but to get it back to defrost, I have to shut the motor off, then when it starts back up, it's back on defrost.
 

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I posted a diagram in here somewhere. I'll post it again when I get on a computer.
 

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I posted a diagram in here somewhere. I'll post it again when I get on a computer.

I was thinking you did too. Sometimes threads get to long and lose posts.
 

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Last winter I went through all that Bulls#*t, with the heater core. I put in a new core from Autozone. This morning as I headed out, I start smelling something familiar(coolant), 20 min later drip/drip/drip on my carpet. WTF!!!!!!!!!!! I figured it would have lasted more than a year. I called autozone, and Its still under warranty, but I don't want to do this again next winter... Fuggin autozone parts! They suck Huevos Peludos!
Guess I'm up next. Hopefully RockAuto cores are better.:Rant:
 

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Last winter I went through all that Bulls#*t, with the heater core. I put in a new core from Autozone. This morning as I headed out, I start smelling something familiar(coolant), 20 min later drip/drip/drip on my carpet. WTF!!!!!!!!!!! I figured it would have lasted more than a year. I called autozone, and Its still under warranty, but I don't want to do this again next winter... Fuggin autozone parts! They suck Huevos Peludos!
Guess I'm up next. Hopefully RockAuto cores are better.:Rant:

Just throwing this out there for the hell of it but check your hose clamps are tight. Sometimes when the seasons change it affects them.
 

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This is the best thread and pictures I've seen on the internet! So hard to figure out how the air flows in the heating/AC system. Thanks a bunch for posting the pictures and diagrams!

My 85 K10 AC is not working and now being winter, I really need the defrost. Years ago, I changed the blower motor a few times with junkyard donations hoping to fix the lack of defrost. Now back in the cold of winter, I need defrost again.

I removed the glove box and the box behind it, attached to the main air distributor/heater box.
I zip tied the rusty door closed, by pulling the arm rod on top toward the other one with zip ties.
I disconnected the defrost door/flap rod and left the vacuum pod rod pushing against it in the position that directs air to the upper defrost conduit.
I put tape around the bad design gap between the upper defrost conduit and the lower distribution box.
I put tape over the opening where the zip tied rusty door is, just to make a tighter seal and push more air to the defrost.
I put tape over the bottom opening for the floor vents (under the vacuum actuated defrost door/flap).
I bought a new VDO Oreilly blower motor for a "1994 GMC 1500 4X4" and installed it. The previous motor had the wrong(d'oh!), "short" cage and didn't push much air.
I turned on the fan and got a huge improvement in defrost air flow!

I would like to completely close off outside air and recirculate inside air if possible to keep the hot air in the cab and odors outside. I'm assuming my vacuum pods don't work though I could be wrong. I'm still not completely sure how the air flows to/from the blower.

Is there a way to manually close the outside air damper flap/door/valve that looks like it's on the right of the passenger side foot well and has something to do with air flow with the blower motor?

I'm also planning to install an eberspacher coolant heater, but I suppose I'll have to ask about installing that in a 6.2L diesel engine forum in order to figure out the coolant flow, etc. Anyway, thanks again for a great forum, the best I've seen so far for these trucks!
 

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