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Discussion Starter · #1 ·
Hello I’m trying to add ac to my truck and am looking for all information pertaining to that. My biggest question is do I need to replace heater box to fit evaporator ? Thank you
 

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It would probably be far easier to add an aftermarket unit that mounts under the dash, it will have the evaporator core in it and will save you from all the hassle of tearing the dash apart.

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If you drive stick it won’t fit under the dash. I don’t see a way of doing it without tearing the dash apart. LMC will have some pics that will show you what you’re up against.
 

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Discussion Starter · #4 ·
It’s an automatic 4x4. Aftermarket system will fit I am just trying to decide if that is the best option
 

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I’ve never liked under dash units. You could also try calling a place like vintage air and see if they have any better suggestions.
 

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Discussion Starter · #6 ·
I’m not a big fan of under dash units either. I did call vintage air and they told me to tear out the heater box and get them measurements and they would build me a system. This is my extra truck that my wife uses just for hauling horses. It kinda sounds like I’m better off just getting a kit and fitting it I thank you guys for the help
 

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Edit:

Wrong post sorry!
 

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Welcome.Google and call a Polar Bear Dealer. They will have all the info you need and probably can do it cheaper than you can.
What year and model level do you have? SE, SLT or full Laramie?
 

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Discussion Starter · #9 ·
I’ve never heard of them. I’ll check into that. I have a 2001 2500 extra cab Cummins. It is as basic as it gets. Not even tilt steering column in this one.
 

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It's not hard to remove the dash.
Just get a donor truck ,it can be a 1500 .You can find them in weeds everywhere.
You,ll have all the under dash stuff you need plus controls and all.
The time evolved would be similar to aftermarket.
I bet you can buy a parts truck cheaper .Then you'll have a system that is easy to get replacement parts in the future.
Chances are there will be other useful parts as well especially if you live where rust is a issue.
 

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I expect that the heater box is the same plastic. Just add the AC components that are needed and different from donor truck. Now you may need a different compressor than the gas trucks as it may mount differently on the Cummins than the V-8's and V-6's.
The vacuum source would easily be adapted. Blend door may be different.
 

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I swapped cabs from a 1500 .
All the stuff under the dash is identical.
All the stuff under the hood is different.
 
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Nice, cost effective trucks are hard to find, especially the lower trim models in decent shape. I may have one in sight, but it doesn’t have AC. I know it was an option on the ST models back when.

Curious if anyone has retrofit AC with used parts?

Installation of the compressor, line set, and condenser is straight forward enough.
The evaporator and controls would be the hard part, not sure if all the controls and potentially even engine controls would need to be tweaked, and also unsure if the hole for the evaporator drain is present on a non-AC truck firewall.

Is assume that the air box/blower box is either the same minus the evaporator core, or that at minimum the space is reserved under the dash for a bigger assembly. Removing the dash woukd stink but not out of the question as that would have to be done if an evaporator sprung a leak.

Has anyone done it? Any ideas?
 

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You may want to check out this thread dealing with the exact same question.
 

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I think the question is if the PCM/ECM is different. These are not mechanical linkage engines, right? The fueling is somewhat controlled by the computer? Not like 16v? So could it be that an AC and non AC computer are different? Wouldn’t that affect the control of relays under WOT and other conditions?

Im also interested in this, linking in here from another thread I started.

Seems like a full airbox with evaporator wouldn’t be too hard to swap assuming that the hole is there for the evaporator drain (I know that’s a sore spot for rust and water entry and whatnot).
 

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I think the question is if the PCM/ECM is different. These are not mechanical linkage engines, right? The fueling is somewhat controlled by the computer? Not like 16v? So could it be that an AC and non AC computer are different? Wouldn’t that affect the control of relays under WOT and other conditions?
Let me start by saying I don't know for certain if the ECMs are different between AC and non-AC trucks. My guess is no. Watching my Quadzilla gauges, what I believe happens when the AC is turned on is the ECM looks at the engine load and throttle position and makes adjustments accordingly. I don't think the PCM would play a role in any of this. Hopefully someone can chime in and confirm this or not.
 

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I’m curious if anyone has a non-AC truck that can have a look at a few things.

I’m curious if the heater box is the same. The FSM indicates that:

931258

Note the comment that there is an air restricted plate in the box. I’m curious if the box is otherwise the same, and more specifically, if the evaporator drain is present in non-AC trucks.

Im also curious what the air restrictor plate looks like…

I would assume that the blend door and all the rest is the same, and that the destructor could be removed and an evaporator installed.
 

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Removing the dash might seem daunting but there's nothing to it but to do it.
Your over thinking this.
If the drain hole isn't there just drill one.
It's all simple you just got to get your hands dirty.
 
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Removing the dash might seem daunting but there's nothing to it but to do it.
Your over thinking this.
If the drain hole isn't there just drill one.
It's all simple you just got to get your hands dirty.
Not opposed to getting in there and dirty. It’s for a truck that I don’t own yet… so there’s lots to think about and decide and plan yet.
 
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