2004 A/C Problem: Dual Climate Control Valve, Compressor, what else?

Hello,

Trying to troubleshoot my A/C problem on a 2004. It stopped blowing cold air a few weeks ago.
The DATC self diagnose does not return any relevant code.
I can see that when I turn the AC ON, the clutch on the compressor does not engage. I see in the service manual that there could be many reasons for that, including low refrigerant pressure.
I can bypass the clutch relay (relay 08 under the hood) and the clutch will engage, but still no cold air. I tried adding refrigerant with the relay bypassed and the clutch engaged, but the pressure goes high very quick, as if there was no need for more refrigerant.
I am at loss here. Any suggestion?
Also, I have read on this forum that the dual climate control valve stuck open on hot coolant was a common issue. Am I correct in assuming that if that was my problem, then the compressor clutch would still be activated by the PCM? Has anybody here who experienced the DCCV failure ever checked what their compressor was doing?

Thanks for the help!
Alex
 

biddle

Forum Moderator
Staff member
Please put the model year in the subject on future posts. I added for you. There are many threads discussing A/C so you might want to spend some time using the search feature of our site.
model-year-TBF.jpg
 
Put a set of gauges on both low and high side. See what pressure is at rest, then
bypass relay and see what pressures you get when compressor is running
bypassed. There is a low pressure switch, and a high pressure switch.

From what you posted, sounds like very low or 134a. When you add 134a have
freon tank upside down to add liquid very slow, or unit will cycle frequently.
 
A/C systems have become very fussy about the amount of Freon to work the system. The quantity needed is posted on a sticker under the hood. Years ago there was more reserve, but due to the environmental concerns of Freon leaks the systems have been tuned to only work on the smaller specified amount. Over or under the by just a few ounces and performance is greatly affected. Gauges are an essential tool in diagnosing A/C problems.
 
Hello,

Trying to troubleshoot my A/C problem on a 2004. It stopped blowing cold air a few weeks ago.
The DATC self diagnose does not return any relevant code.
I can see that when I turn the AC ON, the clutch on the compressor does not engage. I see in the service manual that there could be many reasons for that, including low refrigerant pressure.
I can bypass the clutch relay (relay 08 under the hood) and the clutch will engage, but still no cold air. I tried adding refrigerant with the relay bypassed and the clutch engaged, but the pressure goes high very quick, as if there was no need for more refrigerant.
I am at loss here. Any suggestion?
Also, I have read on this forum that the dual climate control valve stuck open on hot coolant was a common issue. Am I correct in assuming that if that was my problem, then the compressor clutch would still be activated by the PCM? Has anybody here who experienced the DCCV failure ever checked what their compressor was doing?

Thanks for the help!
Alex
Hi Alex, since you did add some refrigerant, I recommend you connect a set of gauges and check the pressures in the system before attempting anything else. You do need the compressor running to do that and if you are unfamiliar with A/C repairs you may want to pay for this part. Typically the low side runs 25-40lbs and the high side is typically twice the ambient temp plus 50. So at 90 degrees outside it would be in the 220-250lbs. Usually if you overcharge with feon the compressor will begin to knock and you must purge the excess or risk damage to the system. Once you can confirm that the pressures are okay, then move on to additional diagnostics. By the way assuming the refrigerant level is fine and while running,feel he suction line (low pressure). It should be ice cold. If that is the case then begin looking at the controls. I had a case last year where my Ford dealer told me my compressor was bad because the drivers side blew cold air and the passenger side blew luke warm air. Mae no sense to me. A couple grand expense was not okay with me based on their best guess. I had also a problem with ignition and the engine sputtering and stalling. long story short I decided to Replace the computer. That was still expensive but Cheaper than the compressor but all problems were solved. I don’t know if this helps you at all, so good luck and do let us know how it works out. Be safe out there, DennisC.
 
Hello,

Trying to troubleshoot my A/C problem on a 2004. It stopped blowing cold air a few weeks ago.
The DATC self diagnose does not return any relevant code.
I can see that when I turn the AC ON, the clutch on the compressor does not engage. I see in the service manual that there could be many reasons for that, including low refrigerant pressure.
I can bypass the clutch relay (relay 08 under the hood) and the clutch will engage, but still no cold air. I tried adding refrigerant with the relay bypassed and the clutch engaged, but the pressure goes high very quick, as if there was no need for more refrigerant.
I am at loss here. Any suggestion?
Also, I have read on this forum that the dual climate control valve stuck open on hot coolant was a common issue. Am I correct in assuming that if that was my problem, then the compressor clutch would still be activated by the PCM? Has anybody here who experienced the DCCV failure ever checked what their compressor was doing?

Thanks for the help!
Alex
Check the holes where the AC condensation comes out, see if they are plugged. Good luck
 
Hello,

Trying to troubleshoot my A/C problem on a 2004. It stopped blowing cold air a few weeks ago.
The DATC self diagnose does not return any relevant code.
I can see that when I turn the AC ON, the clutch on the compressor does not engage. I see in the service manual that there could be many reasons for that, including low refrigerant pressure.
I can bypass the clutch relay (relay 08 under the hood) and the clutch will engage, but still no cold air. I tried adding refrigerant with the relay bypassed and the clutch engaged, but the pressure goes high very quick, as if there was no need for more refrigerant.
I am at loss here. Any suggestion?
Also, I have read on this forum that the dual climate control valve stuck open on hot coolant was a common issue. Am I correct in assuming that if that was my problem, then the compressor clutch would still be activated by the PCM? Has anybody here who experienced the DCCV failure ever checked what their compressor was doing?

Thanks for the help!
Alex
If gauges say 134a is good, then go to DCCV valve.

Tap/rap it with long handle something and see if it releases valve solenoids.

If that makes no difference or does not change or get the hot air to stop out the center dash vents, then remove and clean or replace your temp sensors. One is down under in AirBox and the other is up under steering column.

I replaced my sensors after replacing the DCCV valve 2 times ( Mopar).

Compressor and refrigerant were never an issue.
Seems as if compound problem for me was temp sensors dirty or weak. Cheap enough at Oreillys.

By the way my 2004 does not have a cold air mix door as earlier models have so the diagnostic code suggesting a fault is erroneous. I forget what that code is right now but the assumption is that it is a fault when it does not exist. Sometime after 2002 Ford altered that component and did not reprogram the fault finding program.

You won’t realize that until you tear open the dash to get in the airbox and find that you wasted a lot of time. I followed the Service Manual.


This is a complex problem. My DCCV tap method worked two years later. Quick result.

Good luck
 
If gauges say 134a is good, then go to DCCV valve.

Tap/rap it with long handle something and see if it releases valve solenoids.

If that makes no difference or does not change or get the hot air to stop out the center dash vents, then remove and clean or replace your temp sensors. One is down under in AirBox and the other is up under steering column.

I replaced my sensors after replacing the DCCV valve 2 times ( Mopar).

Compressor and refrigerant were never an issue.
Seems as if compound problem for me was temp sensors dirty or weak. Cheap enough at Oreillys.

By the way my 2004 does not have a cold air mix door as earlier models have so the diagnostic code suggesting a fault is erroneous. I forget what that code is right now but the assumption is that it is a fault when it does not exist. Sometime after 2002 Ford altered that component and did not reprogram the fault finding program.

You won’t realize that until you tear open the dash to get in the airbox and find that you wasted a lot of time. I followed the Service Manual.


This is a complex problem. My DCCV tap method worked two years later. Quick result.

Good luck
Thanks.
I agree that the sensors are also a probable failure. However, the sensors would dictate if the clutch needs to engage or not. In my case, I don't get cold air even I bypass the clutch relay, making the clutch engage and the compressor compress. You would think I would get cold air when the compressor runs...
I changed the DCCV yesterday just for the fun of it, and it did not change anything in terms of compressor clutch behavior. I am pretty sure it was not for nothing as the old DCCV seemed to let the hot coolant flow toward the cabin, and the new one does not.
At this point I need someone to check the refrigerant pressure for me. I am bringing the car to a pro next week.
 
Hi Alex, since you did add some refrigerant, I recommend you connect a set of gauges and check the pressures in the system before attempting anything else. You do need the compressor running to do that and if you are unfamiliar with A/C repairs you may want to pay for this part. Typically the low side runs 25-40lbs and the high side is typically twice the ambient temp plus 50. So at 90 degrees outside it would be in the 220-250lbs. Usually if you overcharge with feon the compressor will begin to knock and you must purge the excess or risk damage to the system. Once you can confirm that the pressures are okay, then move on to additional diagnostics. By the way assuming the refrigerant level is fine and while running,feel he suction line (low pressure). It should be ice cold. If that is the case then begin looking at the controls. I had a case last year where my Ford dealer told me my compressor was bad because the drivers side blew cold air and the passenger side blew luke warm air. Mae no sense to me. A couple grand expense was not okay with me based on their best guess. I had also a problem with ignition and the engine sputtering and stalling. long story short I decided to Replace the computer. That was still expensive but Cheaper than the compressor but all problems were solved. I don’t know if this helps you at all, so good luck and do let us know how it works out. Be safe out there, DennisC.
Any suggestions helps, thank you.
You are right that one of the compressor tubes should feel cold.
In my case, even with the compressor running (clutch relay bypassed to ON), there is no change in temperature on any of the tubes. That tells me either the refrigerant is gone (weird, the gauge on the can does read pressure on the low side), or the compressor is not compressing because it is shot, or something is clogged somewhere.
Last option sounds more likely. I would think if the compressor was shot, the climate control would still engage the clutch, at least for a minute, but it is not the case. Maybe the high pressure switch is triggered because the line is clogged? I don't know.
I am taking the car to an A/C guy to read the high and low sides pressure and we will see from there.
 
Thanks.
I agree that the sensors are also a probable failure. However, the sensors would dictate if the clutch needs to engage or not. In my case, I don't get cold air even I bypass the clutch relay, making the clutch engage and the compressor compress. You would think I would get cold air when the compressor runs...
I changed the DCCV yesterday just for the fun of it, and it did not change anything in terms of compressor clutch behavior. I am pretty sure it was not for nothing as the old DCCV seemed to let the hot coolant flow toward the cabin, and the new one does not.
At this point I need someone to check the refrigerant pressure for me. I am bringing the car to a pro next week.
The sensors determine whether the DCCV solenoids open and close. Think of it this way, the A/C works all time then the DCCV adds hot coolant to heater core as deeded to meet mix requirement of selected temperature left or right. The compressor clutch kicks on or off based on refrigerant pressure. Our dash outputs are a mix of full time A/C with added or subtracted heat.
 
The sensors determine whether the DCCV solenoids open and close. Think of it this way, the A/C works all time then the DCCV adds hot coolant to heater core as deeded to meet mix requirement of selected temperature left or right. The compressor clutch kicks on or off based on refrigerant pressure. Our dash outputs are a mix of full time A/C with added or subtracted heat.
Gotcha. I still don't think the sensors are the issue here. Good or bad, the compressor low pressure line should be cold when the compressor is running -just like you said- but it is not the case here. But thanks for the clarification.
 
Any suggestions helps, thank you.
You are right that one of the compressor tubes should feel cold.
In my case, even with the compressor running (clutch relay bypassed to ON), there is no change in temperature on any of the tubes. That tells me either the refrigerant is gone (weird, the gauge on the can does read pressure on the low side), or the compressor is not compressing because it is shot, or something is clogged somewhere.
Last option sounds more likely. I would think if the compressor was shot, the climate control would still engage the clutch, at least for a minute, but it is not the case. Maybe the high pressure switch is triggered because the line is clogged? I don't know.
I am taking the car to an A/C guy to read the high and low sides pressure and we will see from there.
I think taking it to an AC guy might be the best choice based on what you have shared at so far. I have all the manuals for the car and the climate control section contains 121 pages of diagnostic instructions. Crazy but very detailed. Too much to reproduce here. That said here are a couple of points to keep in mind.
1. You spoke of the DATC And if I understand you correctly, you said that the compressor clutch does not engage when you switch on the AC. But the DATC can be overridden by using manual mode. in fact this is one of the tests. So what happens if you select the dash vent button + AC Override button? Does the compressor clutch engage and run then? If it does thenthat part of the system is working. If not there is a more involved test actually nine of them, that requires gauges, and testing equipment and generally points toward the PCM as the possible culprit.
2. if the system sounds normal with the compressor running it can be completely empty, full with Freon, or slightly low or high. Only having gauges can tell you which one of them is true.
3. if there were a clog or blockage in the system (that would be bad) when you did override and engage the clutch, the engine would immediately stall because the compressor would lock up as it cannot push the compressed gasses under very high pressure past the blockage, alternatively the belt would scream as it slips around the pulley that is unable to turn the compressor. So I think you can eliminate that one.
sorry but that’s about as much as I can cover in a thread. good luck, Dennis
 
I think taking it to an AC guy might be the best choice based on what you have shared at so far. I have all the manuals for the car and the climate control section contains 121 pages of diagnostic instructions. Crazy but very detailed. Too much to reproduce here. That said here are a couple of points to keep in mind.
1. You spoke of the DATC And if I understand you correctly, you said that the compressor clutch does not engage when you switch on the AC. But the DATC can be overridden by using manual mode. in fact this is one of the tests. So what happens if you select the dash vent button + AC Override button? Does the compressor clutch engage and run then? If it does thenthat part of the system is working. If not there is a more involved test actually nine of them, that requires gauges, and testing equipment and generally points toward the PCM as the possible culprit.
2. if the system sounds normal with the compressor running it can be completely empty, full with Freon, or slightly low or high. Only having gauges can tell you which one of them is true.
3. if there were a clog or blockage in the system (that would be bad) when you did override and engage the clutch, the engine would immediately stall because the compressor would lock up as it cannot push the compressed gasses under very high pressure past the blockage, alternatively the belt would scream as it slips around the pulley that is unable to turn the compressor. So I think you can eliminate that one.
sorry but that’s about as much as I can cover in a thread. good luck, Dennis
I have to go back and forth with the air flow buttons until I finally get the cold air to come out the top. Sometimes cold on driver's side and hot on the other. I made the mistake of going to the dealer on this and after spending a lot of $ it was still the same issue. As long as it eventually comes on I'll live with it.
 
Fixed!
Took it to an A/C guy. The second he plugged his machine into the high pressure and low pressure ports and did his thing, the compressor engaged. He said there was no refrigerant left in the system. Now, why is it that when I plugged in the refrigerant can before, I read proper pressure after a few seconds, yet the compressor never engaged, I do not know. I am going to guess it has something to do with the high pressure end...
Anyways, after a full 28 oz charge with UV dye and a week of running, the compressor was covered with yellow. That was the culprit, as simple as that.
I've had a new Motorcraft compressor and drier installed for a few weeks now, and the AC is working great.
 
Hello,

Trying to troubleshoot my A/C problem on a 2004. It stopped blowing cold air a few weeks ago.
The DATC self diagnose does not return any relevant code.
I can see that when I turn the AC ON, the clutch on the compressor does not engage. I see in the service manual that there could be many reasons for that, including low refrigerant pressure.
I can bypass the clutch relay (relay 08 under the hood) and the clutch will engage, but still no cold air. I tried adding refrigerant with the relay bypassed and the clutch engaged, but the pressure goes high very quick, as if there was no need for more refrigerant.
I am at loss here. Any suggestion?
Also, I have read on this forum that the dual climate control valve stuck open on hot coolant was a common issue. Am I correct in assuming that if that was my problem, then the compressor clutch would still be activated by the PCM? Has anybody here who experienced the DCCV failure ever checked what their compressor was doing?

Thanks for the help!
Alex
2005 had similar problems. Freon charge was low which is usually why the clutch will not engage. Dual heat control valve failed open - Easy way to checkthat is too check if the hoss are hot, pinch them off with a couple of clamps or visegrips. But your freon charge is most likely low.
Dave
 
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