Hello, I just joined the forum so this could be the wrong place, so apologies before hand.

To the point, I recently purchased a 2009 Ranger Sport 2WD with the 4.0. It has manual locks and windows, everything is stock.
The only thing I wish to do to it is add factory A/C, as it does not possess it. I was wondering if it was worth doing it myself - and if anyone had done it, how much would I expect it to cost me.
I do have moderate mechanical experience, though I have never tackled a job such as this. I am willing to learn and try, though.

So, that is about all I have to ask right now. Aside from recommended methods on where to acquire the parts, and whether or not I should just pay a shop to do it.

If you would like more information about my Ranger's specs, tools I have, and anything else I will gladly do so.

Thank you!

 

Welcome to the forum

Thats a hard question to answer because the Engine Computer(PCM) runs the AC its not a separate system, so I am thinking Factory AC wouldn't be an option without swapping out the computer and wiring harness

You would need to use Factory parts but could then use your own controls, its really just an ON/OFF switch, all AC systems work that way
The TEMP control just controls the heater, has no AC control, just FYI

The hardest part will be pulling out the dash to install the AC/heater box in the engine bay, you need to pull out the dash to unbolt the heater box and then install the AC/Heater box with Evaporator inside it, thats the part that cools the air going into the cab from the blower/fan

Then 4.0l AC compressor and bracket, and Condensor(in front of radiator) also the hoses with pressure switches, new receiver/drier
And a new AC fan belt, lol, the easy part

You can then just add a switch to activate compressor's clutch relay to start AC cooling
You could retro fit a Ranger AC climate control to do this, it does have 12v OUT when AC is selected which can be use to activate clutch relay, so it would "look like factory"

 

So, if I am correct. I could theoretically hook up the factory components necessary, and then have it activate by a small toggle switch tucked away somewhere in the cabin?

 

Yes, get all the factory parts from/for that engine model and use your own relay and switch to turn on the compressor's clutch

As said AC is on or off there is no temp control

You would need some wiring of course, so when pulling out the system leave any connectors in place and cut the wires, leaving enough so you can splice your wires to them
There are two pressure switches, these are normally closed switches, either will OPEN if pressure is too low or too high, this is to protect the system

Ford Factory and most others do this for these switches
Ground-------------pressure switch----------------------pressure switch----------------------relay(85)<<<<<<all in engine bay

So when pressure is OK the relay is grounded thru the switches, if either pressure switch goes out of range then no Ground and relay opens, turning off AC compressor

Then in the cab you would splice into a Key ON 12volt wire, hook that to your switch, and then run a wire thru the firewall from the switch to the relay(86)

Then you need 12volt power for the clutch itself, so inline fuse(10amp) power to Relay(30), and wire out(87) to clutch on Compressor
Compressor clutch usually comes grounded to compressor case with diode in place

Relays have 4 wires
85 and 86 are to activate relay, 0.5amp draw so can be added to any fused circuit without effecting it
30 and 87 carry the LOAD, the higher amps to power a device, these two wires are connected together when relay is activated

Visual reference here: http://www.gtsparkplugs.com/images/m...iring-840x.jpg

87a is not used in this application but can be there depending on the relay you get, doesn't hurt anything, just not hooked up

If you are wondering where the odd numbering on relays comes from................................its German, VW specifically, those were the wiring numbers from first commonly used relay in a VW, or so the story is told, lol

 

Awesome! Thank you very much.

I got to say, asking this question on Reddit was extremely fruitless and then I try here and you give me an extremely detailed explanation.

Seriously, thank you.

Hopefully, I can get this started this year before the summer heat kicks in. If I do end up doing this myself, this is going to be a fun little project.

 

The hard part is swapping in the heater/AC box, as said, but if you hit a wrecking yard with a 2001-2011 4.0l Ranger with AC then you will know whats need to be done to swap yours out, after you take out the wrecking yard heater/AC box, lol

And it may be you can pull out the box without going inside the cab, I don't know
But if you do need to pull back the dash in the cab, then I would also replace your heater core at that time, they are not expensive and hard to replace in those years because you have to pull back the dash

Be sure to check any fluid(oil) left in the old AC system for metal flakes, compressors can fail and send metal flakes out into the system
You would need to flush out all the other parts and hoses to get rid of any residue so it doesn't foul/ruin the new compressor

 

Hi Ron,

I really don’t know how AC works but I understand wiring fairly well.

AC compressors seem to kick on and off like they have a mind of their own.

Will home made wiring like you stated above work like factory? Will the compressor run constantly? And if it does is that ok?

I think for aftermarket AC, this is by far the best option. I have gathered all parts including a HVAC panel with AC selection but I don’t think I’m going to even need it. Just use a relay with ON/OFF switch and using the 2 pressure switches inline with the ground wire for the relay to effectively kick the compressor in and out like factory.

This whole setup only requiring 1 relay seems too simple but just clarifying it’ll work before I do it this way.

I haven’t seen anyone else mention wiring it this way but I like this idea the best.

Thanks in advance for your reply,
Zach

 

AC is fairly easy to understand, same setup is used in refrigerators and freezers, and home AC units

When you compress a liquid or gas you heat it up, when you release that pressure the reverse happens, it cools down rapidly

Automotive AC uses a belt driven compressor to compress the liquid "freon", when compressed some of the "freon" will become a gas instead of a liquid because its so hot
It then goes to a Condenser(in front of the radiator) that allows any "freon" that was compressed too much to cool back into a liquid
From Condenser it goes into a Storage tank called Receiver/Drier
This is called the "High Side" of the system, high pressure side, and it has a Pressure switch to shut off compressor if pressure gets too high

From receiver/drier there is a small opening called the Orifice Tube or Expansion Valve
The High Pressure Compressed "freon" escapes thru this opening and rapidly Cools the Evaporator, works similar to Heater core but its Cold not hot
The fan blows air into the cab thru thru Evaporator, cooling the air passing thru it
The uncompressed "freon" then travels back to Compressor to be compressed again
This is the Low Pressure side, and it also has a Pressure switch

When AC system is not used the pressure in "both sides" is equal
When you activate the system the compressor starts up
Once the system is turned on the Compressor is activated and deactivated but either 12v or ground being passed thru BOTH pressure switches
Compressor cycles off if pressure gets too high and then restarts when it drops low enough, this is to prevent blowing off connections from pressure that too high
Compressor will not start or will shut off if Pressure drops too low, this is to prevent compressor from burning out, the "freon" had oil in it, this lubes the compressor internally, with enough "freon"(pressure too low) the compressor will seize up, same as your engine running out of oil


Ford's use an Orifice Tube, the size of the hole to release the High Pressure decides the lowest temp that can be achieved, they are available in different sizes
The lowest temp you want is 38degF
You DO NOT want colder, water freezes at 32degF
So if local air is humid and evaporator gets too cold then water in the air freezes on the evaporator blocking air from passing thru so NO AC
This also happens when you start running low on "freon", the low pressure side is not low enough to shut off compressor but its low enough so Orifice Tube is passing "freon" too fast and you get freezing on evaporator

The water you see dripping from behind passenger side front wheel is from the water/moisture sticking to the evaporator and dripping off as fan blow air thru it, if evaporator is too cold that water freezes

So when you add an AC system, don't forget the DRIP TUBE or you will have a WET passenger side floor board

 

Thanks Ron.

This makes sense. Quite the invension.

If I wire this system with my own harness rather than try to make it factory through the PCM, do you think I will have low idle issue's with my 2.3L i4 at stops and such?

I read another thread saying I need to tap into PCM for it to work properly but I believe grounding through the switches is a good way to go.