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


Bird76Mojo

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Well, two steps forward, one step back.. Then a giant leap for air-conditioned Rangerkind..

Today went something like:

- Install radiator and mechanical fan.
- Shorten lower radiator hose, a little too much but it'll work for now..
- Drag out every spare radiator hose on the farm, including all of them from every parts truck I have.
- Mock up, trim hose, eyeball it, trim in the wrong place a time or two, then figure out a solution using the factory Thunderbird upper hose cut in half that works perfectly.
- Fill radiator with coolant.
- Turn on key, and notice truck is having a hard time starting.
- Notice gallons of fuel are running out from under the truck. Shut off quickly, panic & promptly push truck away from massive puddle of fuel.
- Diagnose and assume it's an injector o-ring because I had the passenger fuel rail loose to install the new heater hose outlet on lower intake.
- Confirmed cracked o-ring, order o-rings at Advance Auto & get 25% discount online. Drive 25 miles to pick up & get groceries while I'm there, brake clean, more coolant, a fuse holder, etc..
- Come home, remove upper intake, loosen fuel rails & remove injectors one by one, remove old o-rings and clean injectors as long as I've already got it apart..
- Install new injector o-rings, clean intake mating surfaces, recoat with Copper Coat, and button everything back up again.
- Truck starts flawlessly. Runs well.
- Bypass A/C cycling switch to get compressor to kick on.
- Notice A/C clutch kicks off on certain fan positions.
- Start probing wires and confirming I selected a power wire from the blower switch that only receives voltage on certain fan speeds.
- Run new length of wire inside dash, and cover it with abrasion resistant fiberglass covering. Hook to fuse box after verifying key-on voltage only.
- A/C clutch now kicks on perfectly at any fan speed. Sweet deal!
- Add partial can of R134a and plug cycling switch back in. Keep monitoring pressures and adding refrigerant. Get two cans in the system total.
- Is now late enough that it's getting colder outside so unsure of how this will affect pressures in the system and overall cooling capability.
- Decide to wait for warm weather tomorrow and go back over the system... Tomorrow is supposed to be 76 degrees outside.


Observations so far:

Temperature at the vents using a thermometer were 48 degrees with an outside temperature of 65 degrees. So I'm not getting the "standard" of 20 degree temperature difference.. Disappointing.

With the A/C system running on high and both doors open, low side pressure was at 35psi after adding two cans of refrigerant. The A/C clutch was staying engaged permanently.

I tried to measure the temperature at the inlet and outlet of the evaporator, but radiant heat from the headers was affecting my infrared thermometer. I may use some old tin to make a temporary heat shield to block the heat from the headers to get more accurate measurements of the inlet/outlet temps.. What I could tell was by feeling the inlet/outlet with my fingers, they were close to the same, but could still vary quite a bit...

Condenser wasn't overly hot. Around 120 degrees if I remember right. You could lay your hand directly on it for a long time, but there wasn't a lot of heat to be pulled out of the air with it being so cool outside. That's why I plan to revisit this again tomorrow when it's hotter outside.

What I'm not sure of is what to do if temps vary at the inlet and outlet. If it needs more or less refrigerant if inlet is higher temp than outlet, or vice-versa..
 
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Uncle Gump

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You made a huge steps man... it all sounds really promising.

Your fingers are more sensitive then you think. The key is to use quick touches. If you keep your fingers on too long they get cold and aren't as sensitive to smallish differences. So just quick touches between the inlet and outlet.

So… I always fill the system slowly and stop adding when the temps equal out. You can probably add slightly more and still be ok. Now if the system is low... the inlet will be colder then the outlet. It's vice versa if over filled and could be accompanied by frost on the outlet line and even a frosty accumulator. If you see that... STOP. You are starting to run the risk of getting liquid into the compressor. The key to a rocking A/C system is getting the refrigerant to boil within the confines of the evaporator.

Sounds like you got this... I'm happy for ya Bird
 

Bird76Mojo

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Thanks man! Couldn't have done it without ya.

It only taking 2 cans of refrigerant really surprised me. I suppose it would have something to do with the hoses being so short, but the biggest difference may be the type of condenser used. The original Ranger condenser probably had much larger internal passages, increasing it's capacity. And it would have been larger as well. I think originally it would have been a tube and fin condenser, where this aftermarket one is a different style that I can't remember the name of right now..

I plan to get back at it tomorrow, but a buddy says we're going fishing so we'll see.. Plus my lawn is like a foot tall after all of the rain lately..
 

Bird76Mojo

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Well, I took a test drive today and covered about 15-20 miles. Here are my results..

- The truck can get very hot when idling with the A/C on high. It didn't boil over or anything, but the temperature gauge was very high. It cooled down quickly though.
- The mechanical fan is a lot more noisy due to the extra heat from the condenser. On the highway and in town it wasn't loud at all though, as long as you're moving.
- The truck idles well, and the IAC takes care of the idle kick-up when the A/C is kicked on. I still need to get my vacuum system plumbed correctly though. It's always tried to stall when coming to an abrupt stop after being at higher revs. I need an intake tube with a fitting on it for the vacuum hose from the oil fill..


This was the temperature in the truck when I first went outside today. Outside temperature was around 76 degrees.

thumbnail (35).jpg



This was the A/C temperature on high after idling for around 15 minutes..

thumbnail (38).jpg




This was the A/C temperature when cruising on the highway at 55-60 mph.

thumbnail (39).jpg




This was the system pressure after idling for around 15 minutes. It may not meet Ranger specs, but it does match up to the temperature/pressure chart pretty well.

thumbnail (36).jpg

thumbnail (37).jpg





The high side is running a little too high, but nothing dangerous so far. I believe I have a little too much refrigerant in the system though. I only got two 8oz cans put in.. I may have accidentally let some out, and the system started performing even better... But seeing how my new compressor has a leak, I imagine the system will correct itself nicely. lol

While it may not be the best performing system in the world, it's a vast improvement compared to not having A/C at all. It made the truck unpleasant to drive in the past and I often chose my other truck on hotter days because of it, so I think this will be my favorite mod to date besides the V8 swap. I'll continue to fine-tune the system in the coming days/weeks..

I didn't come in under my $500 goal, but I stayed close to it if you don't count the tool cost. I can always sell them if need be, but my father is already talking about me making him some new A/C hoses for his Gleaner combine, as the ones on it are the originals and 44+ years old. Plus I now have the crimping tool and around 25+ feet of #6, #8, and #10 barrier hose, so it makes sense to use it on his combine to save money for him.


Future improvement plans:

- I have a nice little plastic shroud I want to install above the fan, though I doubt it will make a difference in performance, it will be a nice safety feature..
- I may start looking at a dual electric puller fan conversion instead.
- I should also start looking in to different ways of exhausting under hood heat, as that is a HUGE contributing factor in overall performance of the truck AND the A/C system.
- I also need to get another piece of radiator hose with a 45 degree angle, as I trimmed a piece too short for the lower hose and it pulls the radiator inward a tiny bit too much for my liking.
 

Uncle Gump

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Bird... I'd say that overall this system is looking like a win. Your high side pressure is a little high... but it cools the high side enough to condense. The true test will be a really hot humid day... it will certainly affect it more. You may very well have to up the cooling fan to counter act. I did wonder too about engine temps.. the added heat load from the condenser has to be overcome. You're on the right track looking into additional air flow. This is also confirmed with the duct temps you're getting big air flow while at highway speeds... That air is cold enough to make you reach for the blend door prior to nut-cicles.

Now you just wait... time will tell you how well this system is sealed up. Refrigerant has a way about letting you know if you didn't do it right.

So… congrats Bird. Not bad for a guy that slept through all his A/C classes.
 

Bird76Mojo

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I think that if I could have made the first condenser I bought fit in the truck, the system would perform even better. It was noticeably larger, but would have required cutting in to the core support too much for my liking..

If this job interview goes well today (and the one tomorrow) I'll make the under hood heat problem even worse next spring. With a SN95 Kenne Bell supercharger...
 

Bird76Mojo

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Now I've got myself wondering about changing out the factory Ford cycling switch, and installing a trinary switch in it's place... Or adding a trinary switch to the system.

Just for electric fan control.

More research and reading to do...
 

Bird76Mojo

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A/C is still working perfectly so far.. Hit the highway with it today and it still cools down to 40 degrees. :cool:

The real test will be after it sits all winter. We'll see how bad the compressor seals are leaking..
 

Uncle Gump

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I figured you should have got some seat time with the new system... a few days were kinda brutal with the humidity. Glad to hear it's doing what it should.

In reality... all of them leak. Some worse the others. Even if you have to top it off every year or two for peak performance... still a win in my book Bird. Nice job!

If you spend considerable time idling or stuck in traffic... kicking the fan on will certainly generate the airflow needed to make the system work. Without a fan... A/C performance certainly suffers. I guess it was one aspect of the system I overlooked. What did you figure out for a switch? Do you have an override switch on the cooling fan now? Or is it just off an engine temp switch?
 

Bird76Mojo

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I figured you should have got some seat time with the new system... a few days were kinda brutal with the humidity. Glad to hear it's doing what it should.

In reality... all of them leak. Some worse the others. Even if you have to top it off every year or two for peak performance... still a win in my book Bird. Nice job!

If you spend considerable time idling or stuck in traffic... kicking the fan on will certainly generate the airflow needed to make the system work. Without a fan... A/C performance certainly suffers. I guess it was one aspect of the system I overlooked. What did you figure out for a switch? Do you have an override switch on the cooling fan now? Or is it just off an engine temp switch?
Right now I'm just running the factory Thunderbird mechanical fan.

I've given some thought to running two 7 or 8" pusher fans as auxiliaries and powering them using a PWM controller. I was reading on some hotrod forums, and a lot of those guys like their mechanical fans, but were having similar problems as me, and they had good luck using a couple small auxiliary fans up front. Full size Bronco guys were also using them.

But the more I go over it, the more I'm leaning towards running two electric puller fans using a PWM controller to cover it all. That way if one fan should quit on me, I'd still have one left to possibly get me home.
 

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thats some serious work.
 

bobbywalter

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yes.

i am extremely busy so not around much the last year....

i feel bad seeing this sort of thing. a stang dealer air F.E.A.D. setup is a bolt in for a v8.....probably have one laying around...mark 7 work good too.


even an explorer setup.


several ways to mod the housing for the hvac as well. or just adapting all of the explorer stuff.


vintage air..or even cold master have very cost effective stuff.

to work within these constraints you chose to do takes serious determination.


i am a lazy bastard when not being paid....especially for my own vehicle... if it will cost me more then 200 bux or will take longer then a day to do it....i wont...

so i am very impressed.
 


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