Let's discuss adding A/C to my 1st gen V8 truck that never had it to begin with..


Bird76Mojo

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Quick run down:

1987 standard cab Ranger, originally a 2.0 5spd with NO A/C.
I swapped in a 1992 Thunderbird 5.0 that came with an A/C compressor but it was mounted low on the drivers side and would have hit the steering gear box. It had to be removed. I also cut the lower half off of that cast aluminum bracket.

I removed the EGR system as well as the air (smog) pump, so I'm relocating the A/C compressor in that location. I've already started on my bracket. I cut the lower part of the cast aluminum smog pump bracket off and have started building a custom steel bracket system based on this design: http://miatav8.blogspot.com/2014/07/ac-conversion-ford-302-passenger-side.html

Here's where the guessing comes in to play:

I'm using the stock Thunderbird FS10 A/C compressor to mock up the brackets, mainly because I already have one, and mounting it is easy with the way it bolts up using 4 bolts. It may be a potential problem because the compressor is a good bit larger than the factory Ranger 2.0 A/C compressor.. So I'm not sure how well it will work with the factory Ranger condenser, evaporator, etc.. I do worry about having such a large compressor with a smaller condenser/evaporator, but from what I've looked up on Rockauto, the Ranger units aren't that much smaller than the Thunderbird units.. I can have custom lines made up where needed, and this site should have the parts I need: https://coldhose.com/

I plan to hit up a local salvage yard to pick up the dash controls that have the A/C button and use that button to trigger a relay to power up the compressor. I'll be using the stock Thunderbird A/C wiring harness to scavenge the wiring plugs from to build a custom wiring loom. I think I understand the wiring by looking at various diagrams online and looking at the Thunderbird harness. I have no need for a WOT cutout relay system in this truck..

So basically I'll be running power to the A/C button in the dash, which when pressed, will trigger a 30 or 40 amp relay to apply full battery voltage to the compressor. The high and low pressure switches should cycle the compressor by being on the ground side of the circuit, disengaging the ground to the relay if they sense a low/high pressure scenario. As shown in this annoying video:


Do you think that running power (to trigger the relay only) through the factory Ranger A/C button on the dash controls will be a problem?

I plan to buy a new compressor since my Thunderbird unit has been sitting for so long. I'll probably also buy a new condenser, evaporator, and receiver/dryer. Do I need an expansion valve? https://coldhose.com/expansion-valves.html

So Ranger community, school me on how stupid I am here. :not_i:



Also, since everyone likes pictures..



Alternator/smog pump bracket removed from engine. (that is PB Blaster running down the cylinder head)

thumbnail (1).jpg


Alternator/smog pump bracket front view.

thumbnail (2).jpg


Beginning of cutting the bracket to clear the compressor..

thumbnail (3).jpg


Sizing things up to get an idea for my bracket.

thumbnail (4).jpg


Some thick bushings I picked up at the local machine shop to weld to my compressor plate/bracket.

thumbnail (5).jpg


Bracket progress so far, after much measuring, marking, and drilling. There will be another 90 degree bracket like what is show in the link I provided earlier, to provide stability to the mount. Possibly a threaded link with rod ends so I can fine tune the belt tension if the automatic belt tensioner looks like it needs more travel. I'm going to have the bolt holes milled in to slots at my local machine shop. That way I can fine tune the belt alignment. It will allow the compressor to move fore and aft. He told me today it would cost me $20 to have them milled in to slots..

thumbnail (6).jpg


The nuts are only used as temporary spacers until I can get my bushings trimmed to size. It spaces the compressor body out away from the plate. I'm holding the compressor/plate backwards in this picture.. Long day....

thumbnail (7).jpg


Trimmed alternator/smog bracket reinstalled on the truck for mock up.

thumbnail (8).jpg


Scratching my head trying to figure out which way my A/C lines will have to run..

thumbnail (9).jpg


Hose connection removed so I can remember which fitting is the largest. This will help me when shopping for the adapter to make custom lines.

thumbnail (10).jpg


I actually have the plate/compressor backwards in this picture too. It's been a long day...

thumbnail (11).jpg
 
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85_Ranger4x4

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I think you need an orifice, not an expansion valve. Cheap little piece of plastic.

Running the A/C system off that little button is what the system did from the factory.





The dash portion of the harness comes out of the firewall with the blower motor controls and is a small single pin connector, mine is gray.
 

Bird76Mojo

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Thanks for posting that. I haven't had a look at my EVTM yet. I do worry about idle speed issues when kicking the A/C on, but I'm hoping that the IAC valve takes care of that for me. If not, then I'll bump the idle setting up a little on the throttle body, and then do the idle reset procedure by unhooking the battery, etc.. Then just live with only using the A/C when cruising.

I think it will be just as easy/simple to make my own harness, rather than pulling one from the junkyard. I already have the wire, solder, shrink tubing, relays, connectors, etc. The Thunderbird compressor harness will come in handy when making my own. I'll just cut the 3 pin round connector off and wire in my own. Two of the three wires go to a pressure switch near the dryer, so I'll cut that out of the harness as I believe it may have communicated with the ECM in the Thunderbird. I'll reuse the other connectors.

I'm thinking the way I'm seeing the circuit will work. Hopefully someone with more A/C experience and knowledge will chime in also.

I'm still not sure about orifice tube vs expansion valve.. I'll have to give an online A/C parts supplier a call to see what they recommend. I'm thinking the orifice tube is more of a metering valve/filter in the Ford system, but I'm not sure how they took care of expansion in the system?

One thing is fortunate. I'm mixing Thunderbird and Ranger parts, but for the most part, they used the same connections. Both electrical and for A/C lines. Just a different style of connection at the compressor from what I've seen so far.






I did just find out that my Ron Francis Telorvek system has a connector for the WOT cutout, but the install instructions say it's not used in aftermarket installations. Odd.. It's the grey 2 pin connector at the ECM connector.

https://www.ronfrancis.com/images/MG70-INST.pdf

"NOTE: The short orange and pink wires with the gray connector running out of the computer connector is for the wide open throttle air conditioning compressor clutch disengagement connection. This is not used in an aftermarket application."

I can't find anything in the instructions about the ECM (A9P) controlling/switching a ground to switch on/off the A/C system except for the WOT part of it. Nothing to control the idle speed.. I'm wondering if Ford used the IAC for that.

 

Bird76Mojo

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I'm going to add this video here for future reference. I found it to be very informative.


Also this one from Eric.

 

Bird76Mojo

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Also posting this here for future reference: https://www.techchoiceparts.com/refrigerant-and-oil-capacities/ford

1992 THUNDERBIRD

Year - Model - Refrigerant - Ounces - OilType - Ounces

1989-1993All EnginesR1240.00Mineral7.00


The new Thunderbird compressors on Rockauto are built for R134a and are pre-filled with oil.


1987 RANGER

Year - Model - Refrigerant - Ounces - OilType - Ounces

1987All EnginesR1244.00Mineral10.00






The 1987 Ranger condenser specs are:

Construction6mm
Core Depth (in)7/8
Core Height (in)14-7/8
Core Length (in)20-5/8
Inlet Type# 6 Male Quick Connect
Outlet Type# 6 Male Quick Connect


The 1992 Thunderbird condenser specs are:

Construction6mm
Core Depth (in)7/8
Core Height (in)15-1/2
Core Length (in)26-7/8
Inlet Type# 8 Male Quick Connect
Outlet Type# 6 Male Quick Connect


So I'll need a custom hose but that should be doable from several different websites.



The 1987 Ranger Evaporator specs are:

Width12.000
Width12.015
Height7.9375
Depth4.000
Depth4.040
Core Height Fraction7-3/4
MaterialAluminum
Core Width Fraction12
O-Ring C Number/Desc[38623] / Orifice Tube
DescriptionEvaporator Cores
TypePlate & Fin
Core Width MM304.800
O-Ring C Quantity1
Core Height MM201.613
O-Ring B Quantity1
Core Depth Fraction4
O-Ring A Number/Desc[24608] / Green O-Ring
O-Ring A Quantity1
O-Ring B Number/Desc[24610] / Green O-Ring
Core Height Fraction7-15/16
Core Depth MM101.600



The 1992 Thunderbird evaporator specs are:


Width7.500
Height8.500
Depth3.500
Core Height MM215.900
O-Ring B Number/Desc[24610] / Green O-Ring
Core Width Fraction7-1/2
Core Height Fraction8-1/2
MaterialAluminum
DescriptionEvaporator Cores
Core Depth Fraction3-1/2
O-Ring B Quantity1
O-Ring A Quantity1
TypePlate & Fin
O-Ring A Number/Desc[24608] / Green O-Ring
Core Depth MM88.900
Core Width MM190.500



The 1987 Ranger receiver/dryer specs are:


Body Length10.000
O-Ring A Quantity1
TypeAccumulator
StyleComplete Unit
O-Ring A Number/Desc[24220] / Spring
Length mm254.000
Meets / Exceeds OEM?Yes
O-Ring B Quantity3
Switch Port Dia.MM6.350
O-Ring D Number/Desc[24650] / Green O-Ring
Outlet Fraction5/8
O-Ring B Number/Desc[24670] / Green O-Ring
MaterialSteel
Mounting Hardware?Hardware not included.
Inlet IN0.625
Outlet TypeMale Insert O-ring
Inlet Fraction5/8
Inlet MM15.875
O-Ring C Number/Desc[24610] / Green O-Ring
O-Ring D Quantity2
Switch Port?Yes
Switch Port Dia. IN0.250
Dia. IN3.500
DescriptionAccumulators
Outlet IN0.625
Dia. MM88.900
Inlet TypeFemale Springlock
O-Ring C Quantity2
Outlet MM15.875


The 1992 Thunderbird receiver/dryer specs are:


Body Length6.500
O-Ring A Number/Desc[24676] / Green O-Ring
DescriptionAccumulators
Length mm165.100
Outlet Fraction5/8
Outlet IN0.625
TypeAccumulator
MaterialSteel
Outlet TypeBarb Fitting
Switch Port Dia.MM12.000
Meets / Exceeds OEM?Yes
O-Ring A Quantity1
O-Ring B Quantity1
Inlet TypeMale Springlock
Mounting Hardware?Hardware not included.
O-Ring B Number/Desc[24220] / Spring
Dia. IN3.500
Dia. MM88.900
Outlet MM15.875
Switch Port?Yes
Inlet MM15.875
StyleComplete Unit
Inlet Fraction5/8
O-Ring C Quantity3
Inlet IN0.625
Switch Port Dia. IN0.472
O-Ring C Number/Desc[24670] / Green O-Ring



That's enough for tonight, but I did see on Rockauto that they list expansion valves for the 1987 Ranger that had dealer installed A/C. I'll have to research more about the differences between the expansion valve and orifice tube systems. I know the orifice tube separates the high/low side and meters the flow of liquid refrigerant to the evaporator, but that's about the limit of my knowledge in this area.



GB :)
 

85_Ranger4x4

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Expansion valve/orifice do more or less the same thing, most newer stuff have orifice tubes. Oriface tubes use hi-low pressure switches to cycle the compressor to regulate flow, expansion valves act kind of like the thermostat in the engine cooling system.

 

Bird76Mojo

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https://www.slideshare.net/taufiqatan1/automotive-air-conditioning-training-manual


I forgot to post this info about the diode that's built in to my wiring harness:



It seems the diode is there to protect the ECM on factory systems where the ECM controls switching the ground for the A/C system. When the magnetic field for the clutch is switched off (collapses) there can be large power surges, and the diode protects the ECM. I'll leave the diode in place on my DIY harness even though my ECM won't control anything A/C related.


More info about orifice tubes and expansion valves: https://macsworldwide.wordpress.com/2010/07/14/your-car’s-expansion-valves-and-orifice-tubes-keep-your-ac-flowing/
 

Bird76Mojo

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I've searched high and low for a factory or aftermarket bracket to use an OEM solution when mounting my compressor (any compressor) and I'd have to switch out the entire front accessory drive. Not doing that... Mine works and fits in the truck too well to change it all now. I've searched for weeks on finding brackets. Making my own is no big deal really, and it's cheap.

The problem with switching/mixing capacities in the system comes in to play when adding your charge and calculating the correct amounts of refrigerant and oil for your system, as well as low and high side system pressures once the system is running. The oil, I'll just go with whatever comes in the new compressor when that time comes.. The refrigerant is a different story since I'll be using Ranger condenser/evaporator/dryer units with a Thunderbird compressor as well as shorter lines. The amount of refrigerant should be close to stock though. Physically, the Thunderbird compressor is nearly twice the size of the stock Ranger compressor.

Right now I have one main concern. My Thunderbird compressor doesn't have a high pressure switch on it, or on the line close to it if my memory serves me. I'll have to have another look at the A/C hoses/lines that I have. I do know that there is one hose connection that is a different size between the Ranger and Thunderbird parts, so that's another reason custom hoses will come in to play. The line/hose mounting block on the back of the Thunderbird compressor is vastly different from the Ranger unit as well.

EDIT: after looking through my pictures of the Thunderbird compressor, it appears the block that attaches the hoses to the compressor has a spot for a high pressure switch. I think the switch may be broken off in the following photo but the bottom of it is still attached. I'm not near my parts right now so I'll have a look later on today.



The low pressure (cycling) switch will be on the Ranger parts near the receiver/dryer, so that's good to go..

I'm off to my favorite 1st gen goldmine salvage yard today to see what I can scavenge. (y)




GB :)
 
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Bird76Mojo

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I read a ton last night about expansion valves and expansion blocks, as well as orifice tubes. A lot of sites stated that new higher end cars mostly have expansion valves or blocks because they run much more smoothly and evenly. Not as noisy having the compressor kicking on/off so much.. Apparently, they meter the refrigerant much more smoothly on an as needed basis, which in turn cycles the compressor on/off less. I think the orifice tube solution for this was to use auto-adjusting orifice tubes, though I don't know if Ford ever used those models. To my knowledge Ford only used "fixed" models.
 
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Bird76Mojo

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I just called Four Seasons to ask which of their adapters will fit a Ford FS10 style of compressor and they don't offer much for Ford. They offers tons for GM stuff though.

One adapter that he mentioned looks like it may work well and fit my FS10 compressor body. The lines swivel as well. But it introduces another problem. Finding hose fittings (for the middle of the line) that have the ports attached to them. More searching will be needed..

https://www.4s.com/en/ecatalog?partdetail=12034&view=bg




There's also this adapter: https://coldhose.com/catalog/product/view/id/916/s/ford-fs10-compressor-block/category/39/


But then I'd have to buy hose ends that had 90 degree fittings on the end.


But there's also this adapter which has the ends turned at 90 degrees, but they may send the lines the wrong direction for my application: https://coldhose.com/catalog/product/view/id/913/s/ford-fs10-90-degree-oring-compressor-block/category/39/



There's also this adapter: https://www.summitracing.com/parts/vta-045018



One thing is for sure. They're awfully proud of those adapter blocks. The prices get pretty high on them, but I have seen them for as low as $35 or so.


This page may come in handy later for hose ends with ports: https://nostalgicac.com/fittings-hose-kits/compressor-adapters.html
 

85_Ranger4x4

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I read a ton last night about expansion valves and expansion blocks, as well as orifice tubes. A lot of sites stated that new higher end cars mostly have expansion valves or blocks because they run much more smoothly and evenly. Not as noisy having the compressor kicking on/off so much.. Apparently, they meter the refrigerant much more smoothly on an as needed basis, which in turn cycles the compressor on/off less. I think the orifice tube solution for this was to use auto-adjusting orifice tubes, though I don't know if Ford ever used those models. To my knowledge Ford only used "fixed" models.
That is kind of the jist of what I have gathered over the years too having never came across a system that had the option.

Most farm equipment uses expansion valves... but as you know a cab is pretty much a greenhouse and it takes a lot too keep them cool.
 

Bird76Mojo

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I think the expansion valves or blocks are an older technology and they've been around so long they've been fine tuned to perfection, and maybe that's why higher end cars have them. They meter the flow of refrigerant better. Like a constantly adjusting proportioning valve.

Today at the junkyard I scored the following for $40 total, which was a little high but still cheaper than Ebay:

thumbnail (12).jpg

thumbnail (13).jpg



I also found the parts I need for my delay wiper conversion. $20 is faaaarr cheaper than Ebay stuff for this. I just hope it's all good because out of the dozen or so 1st gens they have, there was only one with delay wipers that I could find. If not, I'll go hit up a couple others and a couple early BII's and see if they have it. The guys are good at exchanging parts for me for free if they're faulty.


thumbnail.jpg


Nothing new on my compressor bracket today, except for the machine shop got my slots milled so it's adjustable fore/aft for belt alignment. He did the sloppiest job I could imagine but I'll do my best to clean it up a little bit..


GB :)
 

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One thing I couldn't find on any Thunderbird today was a high pressure switch. They seem to only have one switch, which is near the dryer/accumulator, unless Ford was really good at playing hide and seek. I believe the one near the dryer/accumulator to be the low pressure switch, but I obviously need to do more research. I'm guessing I still need to include a high pressure switch in my system since the Ranger seems to have one included on newer trucks. I'm just not sure if all generations of Rangers had them. I need to have a look at my EVTM for my 87 and see what it shows.

This diagram only shows one switch. The "AC clutch pressure cycling switch" so maybe it's a binary switch? For both high and low pressure?




One thing I can't see being right is full battery power coming from a relay (relay triggered by my A/C button on the dash) and then going through any safety switches before it goes to the compressor. The compressor can pull some serious amperage and I can't see those switches being able to handle it for very long.
 
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85_Ranger4x4

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I found my engine side harness, it might help.

Only has a place for one switch.



Compressor end complete with diode:



Switch connector:



What plugs into the dash harness (blue), goes to to the ECM, ground and WOT cutout relay:

 

Bird76Mojo

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It does look like my factory Thunderbird compressor block (hose connection to the compressor) has a built-in relief valve, but whatever new adapter I get to hook lines to the compressor doesn't look to have a provision to mount one. So that's another thing I'll have to be sure to adapt in to my hose.

Here's the factory one:




I've been looking on Coldhose.com at some of the switches. I'm liking the sound of using a trinary switch in the system. It has the safety for both high and low pressure as well as another circuit that can trigger an electric fan. I wouldn't have to use that circuit at first, but if I decided I needed an additional electric fan in the future, it would sure make things easier.

Fan on at 242 PSIG, off at 185 PSIG. Low opens at 29 PSIG. High opens at 377 PSIG closes at 369 PSIG

https://coldhose.com/switches/female-7-16-20-trinary-switch.html



I was initially planning on using all factory 1987 Ranger components except for the compressor, but now I'm leaning towards using more universal parts. Using a universal condenser will help with any mounting issues I have because of my V8 swap radiator..

I can still use the factory Ranger evaporator and dryer, and there's a cycling switch port in that side of the system already.



Found this post on another Ranger forum by total accident:

"On my 92, I swapped over the blower motor box, a/c compressor, condensor and interior switch panel. I then got a pigtail connector for the a/c compressor connector and the low pressure switch. I wired in a relay to kick the compressor on and off. It was fairly simple, I found the connector in the engine bay that was for the a/c system, and used the wire on that connector that activates the a/c compressor. It runs to the low pressure switch, and the other wire on the low pressure switch runs to the relay. This is your "switch" for the relay. It cuts current when the pressure rises, and also doesn't allow current to flow when there isn't enough pressure. After that its just a regular relay setup, constant hot, ground, and output to the compressor (compressor needs a ground). Idle boost still works the way it should."

https://www.ranger-forums.com/sohc-2-3l-2-5l-lima-engines-135/installing-air-conditioning-non-ac-ranger-131211/


From what I've read thus far, not all systems used a high pressure switch. The switch Ford used on the accumulator/dryer isn't just a low pressure switch either. They called it a cycling switch. On 47psi / Off 26psi / Off permanently at 0psi

More research is still needed...
 


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