Forgot to mention that I tried checking for codes. Only thing that did was make all the lights in the display light up and stay that way.

 

You know the a/c in my '06 was doing the exact same thing that you described. What I did was jiggle the a/c clutch wire/plug and thats all it took this happened about 2 weeks and its been fine ever since. Why not try it what have you got to lose. Hell it just might work! Good luck to ya!

 

Thanks for the suggestion. At this point I am willing to try anything. I will check all the connections I can find tomorrow. Already spent $100 taking it to a mechanic who I thought would fix it.

 

so you have done this?

Electronic Automatic Temperature Control (EATC) Module On-Demand Self Test
The EATC Module On-Demand Self Test will retrieve on-demand (hard fault) DTCs only, it will not retrieve continuous DTCs. Continuous DTCs can be cleared when exiting the EATC Module On-Demand Self Test. Make sure to retrieve continuous DTCs by carrying out the Electronic Automatic Temperature Control Module — Retrieve Continuous DTCs procedure before clearing any continuous DTCs.

• The EATC Module On-Demand Self Test will not detect concerns associated with data link messages like engine coolant temperature or vehicle speed signals. A scan tool must be used to retrieve these concerns.
• The EATC Module On-Demand Self Test will detect concerns in the system control functions and will display on-demand (hard fault) DTCs for concerns that are present during the self-test. The vehicle interior temperature should be between 4°C-38°C (40°F-100°F) when carrying out the self-test. If the temperatures are not within the specified ranges, false DTCs may be displayed.
• The self-test can be initiated after cycling the ignition switch from OFF to ON. Normal operation of the climate control system stops when the self-test is activated.
• To enter the self-test, press the OFF and DEFROST buttons simultaneously and release, then press the AUTO button within 2 seconds. The display will show a flashing blower icon for 20 seconds, after which all vacuum fluorescent segments will be displayed if there are no on-demand DTCs present. If DTCs are present, the EATC module will display "00 00" and then on-demand DTCs. Record all DTCs displayed.
• If any DTCs appear during the self-test, carry out the diagnostic procedure. Refer to the Electronic Manual Temperature Control (EMTC) Module and Electronic Automatic Temperature Control (EATC) Module DTC Chart and follow the ACTION for each DTC given.
• If a condition exists, but no DTCs appear during the self-test, GO to Symptom Chart Condition: The EATC System is Inoperative, Intermittent or Incorrect Operation.
• To exit the self-test and retain all DTCs, press any button except DEFROST. The EATC module will exit the self-test and retain all DTCs.
• To exit the self-test and clear all DTCs, press the DEFROST button. The EATC module will exit the self-test and all DTCs will be cleared.
• Always exit the self-test before powering the system down (system turned OFF). Once the self-test is exited, the ignition switch must remain ON for at least 30 seconds to allow the door actuators to automatically recalibrate.
• Continuous DTCs will be deleted after 80 ignition switch ON cycles after the intermittent fault occurs.

Electronic Automatic Temperature Control (EATC) Module — Retrieve Continuous DTCs
The EATC module will retrieve only continuous (intermittent) DTCs when carrying out this procedure.

• Retrieval of continuous DTCs can be initiated after cycling the ignition switch from OFF to ON. Normal operation of the climate control system stops when retrieving continuous DTCs.
• To retrieve continuous DTCs, press the OFF and DEFROST buttons simultaneously and release, then press the RECIRC button within 2 seconds. All vacuum fluorescent segments will be displayed if there are no continuous DTCs present. Continuous DTCs are indicated by the presence of the Celsius symbol (°C) on the EATC module display. Record all DTCs displayed.
• If any DTCs appear, carry out the diagnostic procedure. Refer to the Electronic Automatic Manual Control (EMTC) Module and Electronic Automatic Temperature Control (EATC) Module DTC chart and follow the ACTION for each DTC given.
• If a condition exists but no DTCs appear, GO to Symptom Chart Condition: The EATC System is Inoperative, Intermittent or Incorrect Operation.
• To exit and retain all continuous DTCs, press any button except DEFROST. The EATC module will exit the retrieved continuous DTCs mode and retain all continuous DTCs.
• To exit and clear all continuous DTCs, press the DEFROST button. The EATC module will exit the retrieve continuous DTCs mode and all continuous DTCs will be cleared.
• Always exit the procedure before powering the system down (system turned OFF). Once the procedure is exited, the ignition switch must remain ON for at least 30 seconds to allow the door actuators to automatically recalibrate.
• Continuous DTCs will be deleted after 80 ignition switch ON cycles after the intermittent fault occurs.

Electronic Automatic Temperature Control (EATC) Module and Electronic Manual Temperature Control (EMTC) Module Cold Boot Process
The purpose of the cold boot process is to allow the EATC or EMTC module to reinitialize and calibrate the actuators. To carry out the cold boot process, follow the steps below.

1. Turn the ignition switch to the OFF position.
2. Disconnect the EATC or EMTC module electrical connectors.
3. Wait one minute.
4. Connect the EATC or EMTC module electrical connectors.
5. Turn the ignition switch to the ON position.
6. Select any position except OFF on the EATC or EMTC module.

The EATC or EMTC module will now initialize and calibrate the actuators. Calibration of the actuators will take approximately 30 seconds.

 

do you have automatic of manual?? it says you have an SEL which has manual but you mentioned lights

 

I have the electronic one, guess that was an option on the SEL. I did the self test for the codes as described above and I got the flashing blower icon for many seconds then all the lights on the display lit up and stayed on. Reading the instructions above that means there are no DTC's.

I really appreciate the suggestions. I really hope this is something simple. The car only has 61K on it and this is the first problem I have had since the a couple of minor warranty issues the first year I had it.

 

Could be a wiring or relay problem. Basically the PCM just controls the ground of the A/C clutch relay, which turns power on and off to the clutch coil. I would check the connections to the coil as indicated. You might also try swapping the relay to see if it goes away. Another good test would be to pull the relay and install a test light across pins 1 and 2 to see if the PCM is actually turning the clutch on and off that fast.

This car doesn't have a pressure sensor to my knowledge, and it's my understanding the evap discharge temp sensor replaces it to control the A/C cycling.

So I agree that a bad evap temp sensor might be the problem, but I find it interesting your mechanic did this for only $100. Those temp sensors are one of the worst parts to replace because you have to tear the entire dash out to get to it. So you're looking at 2-3 hours of labor there or more (which usually costs more than $100). So my question is, do you trust that your mechanic actually replaced the temp sensor or did he just make 100 fast ones off you?

 

Wow that is interesting. I did not realize the temp sensor was that hard to get to. They charged me something like $15 for the part and $85 for labor which I figure is about an hour's worth of time. I do not have a regular mechanic because I do pretty much all the maintenance and repairs on my cars as I can (just don't know much about a/c). I picked these guys because they were close and they looked legit but this was the first time I had been there. I am starting to have my doubts about them though. And I would think that since their "a/c expert" looked at my car he would have checked everything that has been suggested here.

I will check the wiring before I go anywhere today. Where is the relay located? If I don't get anywhere on the wiring I might just swap that out. Figure it can't be that expensive.

 

He probably replaced the low side switch. Cheap and easy to change. Open hood, look to your left, near the coolant tank. Switch is right there.

 

on a 2008 you can access the sensor from under the dash on the LH side by the accelerator pedal no need to pull the dash. ac clutch relay is spot 41 in the underhood fuse block.

I am intrigued by your car though a SEL with auto climate control is confusing me What other options does it have? pictures?

 

on a 2008 you can access the sensor from under the dash on the LH side by the accelerator pedal no need to pull the dash. ac clutch relay is spot 41 in the underhood fuse block.

I checked, and TaurusBear is right. The temp sensor on this model comes right out of the driver's side of the HVAC box. So it could be done in less than one hour (congratulations to Ford for doing it right!). The PIA ones are clipped to the evap core and you have to get the HVAC box out and opened up to get to it.

The A/C clutch relay is #41 located in the corner of the engine compartment power box.

The mechanic might or might not have checked all the electrical stuff. Most mechanics really aren't very good at electrical troubleshooting. They just swap parts until the problem goes away. If the problem is with the wiring or something (something they can't part swap), most will not be able to figure it out.

 

Of course im right don't doubt the Bear LOL

 

Sorry it took me so long to get back to you guys. Good to know that it's still likely that the mechanic did replace the part they said they did. Checked the only wire connection I saw going to the compressor before taking it out today. Connection seemed good and I followed the wire where it joins others for the alternator. Everything looked fine.

Took it out for a spin and noticed the same thing with the compressor cycling while the car is stopped though I did not notice the air ever getting warm. For some reason that seems to have maybe improved since I got it back to the mechanic. I also cannot be sure it is doing the on/off cycling when the car is moving. It may not be or I just cant hear/notice it click on and off when driving.

I did not get a chance to pick up a new relay but I did find one at the local auto parts store for $16. Guess that would be worth a try. Is there anything else at all that would cause the compressor to cycle like this?

And TaurusBear only other options I have on it are leather and in dash CD changer. Bought it at the end of 08 as a Ford Certified car. Took this pic for you but it came out kind of crappy.

 

Also got this pic. Turned out much better. Still getting used to this camera. h

 

I didnt see any pics. LOL are you sure you dont have a limited LOL Ive never seen a SEL with leather, auto climate and the changer. do you have chrome outside handles, white guages, a clock? auto headlights?

Since i have got mine i have obsessively researched this car and thought i knew everything bout them LOL

 

Really no pics? I see them. I'll try it again. And yes it's an SEL. No chromes wheels, handles or clock. Do have auto headlights though.

 

thats cool your car must have been special ordered.

As far as your AC without taking it in and having a scan tool hooked up it may be impossible to diagnose. To be honest as long as its working I would just deal with it. seems silly to spend hundreds of dollars to fix something that is still working. Then again if you have the money go for it

 

I was just concerned that it was putting unnecessary wear on the compressor acting like this. I plan to keep this car to at least 100K and the compressor's on these cars look like a pain to swap out. I'm going to watch it for now and maybe get a new relay next week. Hate for it to be something that simple and not change it out.

I would have hoped the mechanic I took it to would have scanned everything to find any easy answers. Is there anyway to reset everything myself to clear the computer?

 

you could try this

Electronic Automatic Temperature Control (EATC) Module and Electronic Manual Temperature Control (EMTC) Module Cold Boot Process
The purpose of the cold boot process is to allow the EATC or EMTC module to reinitialize and calibrate the actuators. To carry out the cold boot process, follow the steps below.

1. Turn the ignition switch to the OFF position.
2. Disconnect the EATC or EMTC module electrical connectors.
3. Wait one minute.
4. Connect the EATC or EMTC module electrical connectors.
5. Turn the ignition switch to the ON position.
6. Select any position except OFF on the EATC or EMTC module.

You could prolly disconnect the battery for a while as well

as far as the relay i would bet something else uses the same relay in the under hood box and you could swap them around.

If you do every find out whats wrong if you let me know i can get you directions on how to fix it or wire diagrams i got the Ford repair program for 2008

 

You could try pulling fuses 15, 37, and 45 under the dash at the same time.

P.S. I like your rearview mirror ornament!

 

I'll certainly keep you all informed if I ever get it figured out. I'll look at the relay's as soon as I can. If That doesn't work I will try disconnecting that battery overnight. This is primarily my wife's car and we have different schedules so it may take me a few days. I appreciate all the help.

Just saw your post behlinia, LOL. I don't know why my wife finds the need to keep that there either. Pulling all of those fuses together I'm guessing will reset everything? I'll try that first.

 

That's weird I just checked this forum on my iPhone and the pictures showed up very nice car. You can try the under dash fuse box but be prepared to take up drinking afterwards lol it's the worste design ever lol

 

I have a 2008 Limited and the A/C works most of the time. But at times it blows out warm air, when this has happened I turned the A/C off and back on then it works fine. Not sure of the problem.

 

Thought I would give you all an update. After the wife and I having opposite schedules the past 2 weeks I finally had a chance to look at it again and drive the car. Before taking it out tonight I switched relay #41 and 42. I also disconnected the battery for about a half hour (not sure if that would even do anything). Took it out for a spin and still does the same thing. Tried to pay attention to it the best I could. Like I said before I can only be sure the compressor is cycling on and off at idle and it may not be doing it at all when moving. I did not notice the air ever blowing out warm.

Couple things that I have thought of that make me wonder. The mechanic that replaced the switch stated that Ford had trouble with this switch on older models and had since changed it in some way, so I now have the updated switch. I am certain that before I brought the car to the mechanic the compressor cycling was occurring when the car was moving. I first noticed the problem when driving down the highway and the air started blowing warm out of the vents before coming back on and blowing cold.

My best guess now is that the switch my mechanic replaced fixed the problem while at the same time causing this constant compressor cycling while at idle. I have since had another mechanic tell me this behavior sounds normal to him. I have a hard time accepting this being normal since it did not use to cycle like this when I bought it and it does not sound like others here with similar year models are experiencing this.

For now I am pretty much out of ideas and will just have to watch it.

 

I'm wondering how you're determining when the A/C is on or off? Are you actually watching the A/C pulley and seeing the clutch start and stop spinning?

If you're just going off the temperature you feel coming out of the vents, be aware that the automatic climate control will apply heat in varying amounts depending on indoor/outdoor temps and the intensity of sun. To rule temperature cycling out, turn the temperature setting as low as it goes and monitor the A/C pulley.

Also, the outside air temp will affect the amount of cycling. When the ambinet temp is cooler (60's), then the A/C will cycle much more often than when it's really hot (90's). I see it's warm enough during the day in Buford, but if you're going into work at night and have the A/C on then it might be cycling more.

If you're still concerned, you might consider bringing it into a Ford dealer and having them run diagnostics.

 

When I first noticed the problem weeks ago it was on a hot day (upper 80's) going down the interstate. I had the air set on or near the lowest setting and suddenly felt warm air coming out of vents. This only lasted a moment and IIRC i could feel the compressor kick back on and the air stared blowing out cold.

Today and in the past I have not been visually inspecting the pulley. I know what a compressor cycling on and off sounds like and at idle with the radio off it is obvious that is what I am hearing. Again the air is not blowing out warm anymore so it is working (and according to my mechanic it is working correctly). This evening it was probably upper 70's to low 80's when I drove it.

I am concerned about this putting premature wear on the compressor. Can the dealer really check anything a qualified local mechanic can't? I would hate to waste another $100-$200 just to hear that there is nothing wrong.

 

If you know what you're hearing and can tell the difference between on and off then the hearing method might be acceptable.

Dealer might have some additional diagnostic capabilities with their scan tool, but if spending $100+ to find out nothing is wrong bothers you, then you might have to stick with private mechanics or live with it.

If you're still concerned, you can perform the EATC tests again, and have your mechanic check the system pressures again. Make sure he uses a temperature table to see if the system pressures are acceptable. I would ask him for the numbers and report back with the temperature.

Also, posting a video with the hood open might be helpful. We might be able to judge it better that way.

 

My Kate was acting the same way, get your car up in the air, Ramps whatever, look between the radiator and the condenser from directly under front of the car and check for and clean debris out, blow it out with compressed air... My radiator was totally covered with either dandelion fuzzies or cottonwood fuzzies, and most of all the weird stuff it was doing went away.
It would run hot when the a/c was used, jerked stumbled malfunctioned and usually tripped a flashing check engine light
History, changed a/c compressor the factory one was worn out!
To date she still has a miss when a/c compressor is in use for defrost, a/c is used, sitting at a stop light I can hear, feel it missfire...