Hoping someone can help educate me on the A/C system in my Flex... quick, the backstory...

Summer of 2022 the AC started occasionally acting up, meaning it would sometimes stop blowing cold randomly and instead blow ambient temp. It would resolve itself shortly, for a while. This gradually worsened until suddenly it wasn't working more than it was, and then eventually pretty much never working. Took it to my independent mechanic who looked it over and he concluded the compressor was done. As per our normal agreement I sourced the parts from Rock Auto, using Motorcraft for this project, which included the compressor and some associated parts he said needed to be changed with the compressor.

Got it back, paid the bill, worked fine. Within a couple days it started doing the same thing and would occasionally stop blowing cold and instead blow ambient. I called him right up and he said bring it by, maybe I pinched a gasket and its got a leak. He looked it over and came to the conclusion that the clutch in the new Motorcraft compressor was faulty and I was going to have to warranty the part and put in a new one. Ugh.

So I've got the replacement compressor now, but haven't had time to get the car back to him. However, and I realize I'm not a pro, it just doesn't sit right with me that the compressor is the problem. My gut feels off about it. I ask him about what else it could be and he walks me through a few things, says there wasn't a leak as he recovered to proper amount of refrigerant when he checked it again. He says the relay isn't the issue because he was getting power at the compressor when it wasn't working. He says the pressure switch isn't the problem as it works in conjunction with something?

As I haven't had a chance to get it back to him to have the compressor swapped out I thought I'd try and educate myself on the system and see if maybe we are missing something.

I read that the clutch should spin freely/smoothly by hand with the engine off: it does.

I found the relay for the compressor clutch and swapped it with the fuel pump relay which was obviously fine as the car runs just dandy... well, the car continues to run just dandy and the AC continues to behave the same way. Scratch that relay.

I'd like to use a jumper to activate the electromagnet to make the clutch pop in, but I don't know what pins to jump at the relay mount. Anybody have that info?

Then I remembered that there is some sort of relationship between the electric fans and the AC system. I realize, of course, that when the fans are on the AC seems to be working. When the fans aren't on, it sometimes isn't working, sometimes is, but for an unknown length of time.

The car has 3 fan relays... 2 of them are identical to some of the trailer light relays so I swapped those around, no apparent change in AC behavior so those 2 seem to be ok. The third relay is different and the only one in the car, so I couldn't change it around until this morning. I just swapped it out for an identical one from a different vehicle. We'll see if it has some effect... however, the fans cycle on and off a lot while the car is sitting at idle on this cool morning. The car wasn't even at operating temp but with the AC on max cold the fans would cycle on for about 30 seconds then shut down for a minute or so and would repeat.

Should the electric fans be on all the time the AC is on, or is it only when called for based upon a temperature somewhere? If so, what temperature is it reading? Coolant?

Do I possibly have a bad fan controller and that is the cause, or is the fan a symptom and something else is a cause, or is the fan acting normally?

What else can I tinker with for now?

quote:

Originally posted by Ozarkwoods:
I was just listening to a YT video on an AC sporadically working. I ended being a part in the compressor that was not serviceable acting up. The poster tried to pull it out from the compressor but it could not be removed with out damage. I don’t believe they use an electro magnet any longer. This part was the part that took the electro magnets place.

I suppose that is what the mechanic concluded, and if nothing else changes I will have him swap out the compressor again when I can get him the car, but it just doesn't sit right that it is having essentially the exact same issue that it did prior to any work being done on it. Logically that makes me suspect perhaps the compressor was never the problem.

When it does work it works great, nice and cold. I'll feel better if I can exhaust some other options since it'll likely be at least a week before I can get the car to him. I've got time to check some stuff off the list if for no other reason than I'll learn some things.

I just was listening to a YT with the same symptom sporadic ac. It was a part in the compressor that took the place of the electromagnet clutch that is no longer used. The part was not serviceable. A new compressor was bought and it fixed the issue.

I’d try and find some forums for Ford and see if any flex owners have similar issues.

You could also pay for a month of Alldata for your flex and read about the ac system.

Repair manual -

quote:

Originally posted by mrvmax:
I’d try and find some forums for Ford and see if any flex owners have similar issues.

You could also pay for a month of Alldata for your flex and read about the ac system.

Repair manual -

I was a member here when we had our Flex

https://www.fordflex.net/forums/index.php

quote:

Originally posted by thumperfbc:

quote:

Originally posted by Ozarkwoods:
I was just listening to a YT video on an AC sporadically working. I ended being a part in the compressor that was not serviceable acting up. The poster tried to pull it out from the compressor but it could not be removed with out damage. I don’t believe they use an electro magnet any longer. This part was the part that took the electro magnets place.

I suppose that is what the mechanic concluded, and if nothing else changes I will have him swap out the compressor again when I can get him the car, but it just doesn't sit right that it is having essentially the exact same issue that it did prior to any work being done on it. Logically that makes me suspect perhaps the compressor was never the problem.

When it does work it works great, nice and cold. I'll feel better if I can exhaust some other options since it'll likely be at least a week before I can get the car to him. I've got time to check some stuff off the list if for no other reason than I'll learn some things.

I surely understand that.

When it’s blowing ambient temperature air is the compressor running?

quote:

Originally posted by arfmel:
When it’s blowing ambient temperature air is the compressor running?

No, when it is blowing ambient the compressor clutch is not engaged and it isn't running.

The question is why isn't it running? A problem with the compressor or something else in the system shutting it down? Hmmm

I found a reference online to jump pins 3 and 5 on the clutch relay socket to get the clutch to activate so I gave that a try and it doesn't seems to work. I can't see the clutch from where I need to stand to jump the socket but I should be able to hear it closing and it didn't. I was able to hear it clicking to engage. I jumped and unjumped the clutch several times... it responded correctly each time. This further makes me think the clutch is not the issue as my gut was telling me.

Additionally, I noticed that all 6 relays of that type were installed upside down (comparing pin numbers on the relay itself to the service wiring diagram)... Those 6 relays include some trailer lighting relays (that I wouldn't notice not working) as well as the AC Clutch (obviously worked sometimes), reverse lights (as far as I know working fine), and the fuel pump (clearly working fine despite the relay being backwards). I corrected the orientation and started the car... it ran fine.

quote:

Originally posted by P250UA5:
I was a member here when we had our Flex

https://www.fordflex.net/forums/index.php

Thanks, I'm finding a fair amount of AC related posts on there. It seems others are having issues. I'll dig through there for a while.

This message has been edited. Last edited by: thumperfbc,

As a Luddite I’m suspicious that there’s a computer board somewhere that’s botched up. Everything is computer driven nowadays and it’s the bane of mankind.

quote:

Originally posted by arfmel:
As a Luddite I’m suspicious that there’s a computer board somewhere that’s botched up. Everything is computer driven nowadays and it’s the bane of mankind.

Yes, the thought has crossed my mind. My $50 code reader is not capable of displaying live data like refrigerant pressure or the status of the AC power command...

I studied the wiring diagram and think I have somewhat of a handle on how things flow... I should be able to check for power at the PCM relay that in turn feeds the AC clutch relay... That doesn't settle things, but it is a few more things I can cross off the list.

Not sure yet how I confirm if the fan controller is working properly, or even if it is something to look at in this scenario. I'm happy enough trying to learn this sort of thing while I have to wait anyway.

If I'm really lucky the problem will be resolved with the high fan control relay that I swapped out this morning... Won't know until I can drive the thing. The one HFC relay that was in there DID have a cracked case, so it took some sort of hit/damage at some point.

I’ve discovered voltage drop at the compressor clutch connector itself. Measuring voltage with car and AC on is 10.5v. Measuring between the hot pin of the same connector and the engine block directly is 14+v.

Measuring with car off is 10.5v between pins and 12.5ish between hot pin and engine block.

Is that voltage drop enough to prevent reliable clutch activation? How do I find the problem in the ground wire? The wire gets combined several times over until it was in a large bundle.

You are not voltage drop testing, you need put one lead on the positive terminal of battery, the other lead on the positive terminal of the connector (back probed, everything connected with the A/C commanded on, power to it).
https://www.alldata.com/sites/...rop__test_122718.pdf

Is it a one wire connector? if so, if you apply 12v to the disconnected wire on the compressor clutch, does it engage?

quote:

Originally posted by rizzle:
You are not voltage drop testing, you need put one lead on the positive terminal of battery, the other lead on the positive terminal of the connector (back probed, everything connected with the A/C commanded on, power to it).
https://www.alldata.com/sites/...rop__test_122718.pdf

Is it a one wire connector? if so, if you apply 12v to the disconnected wire on the compressor clutch, does it engage?

One lead on the positive battery and one lead on the positive at the connector will not measure voltage, there is no circuit there. That would allow me to check continuity, though. Measuring voltage at the source (relay box) and then again at the end (connector) and finding a difference is checking for drop. HOWEVER, I’m still dumb. The connector I had been testing was NOT the clutch coil connector, it was the control valve or something… aka, the wrong one, and irrelevant. The voltage I read is perhaps perfectly appropriate. In any event I don’t believe it has a bearing on the clutch engaging.

It is a 2 wire connection on the real connector. I can not get to that connector to unplug it and check for voltage, unless I pull the fan assembly. That being said I can bypass the relay and send 12v down the circuit at the relay box. When I do the clutch engages, everytime. This makes me thing the compressor is fine and doesn’t need changing.

I don't mean to come across as an ass, just trying to help, but you need to learn the basic stuff. As you mentioned before, you do not have the scanner to command on or off, or check body codes.
Well guess what, that is how it's done nowadays.
Your comment about volt drop testing completely wrong, if there is power on that circuit, testing from the positive terminal of battery to the power connection on that clutch will most definitely give you volt drop reading, did you read the testing link above, or just assuming it's wrong.
I'm probably just a pest, but I don't like seeing wrong information posted on a forum of this caliber.

quote:

I don't mean to come across as an ass, just trying to help,

Me too. I recommend that you quit jumpering and testing before you let the smoke out of something.

Problem found, faulty pressure switch.

Good thing I didn't let the smoke out during my testing.

Good. Thanks for letting us know.