for access to Reviews and Discussion of the 2016 and 2017 Ford Explorer Tech Tips, How to Articles, Off-Road Modification, Events, and more!

Register Today It's free! This box will disappear once registered!

Automatic climate control problems

Discussion in 'Stock 1995 - 2001 Explorers' started by Ranger Rick, November 7, 2011.

  • Searches ExplorerForum.com
    1. Ranger Rick

      Ranger Rick Active Member

      Joined:
      December 18, 2002
      Messages:
      111
      Likes Received:
      0
      Trophy Points:
      16
      City, State:
      Rochester, NY
      Year and Model:
      '98 Mountaineer AWD
      My '98 Mountaineer has issues with the automatic climate control. Some time back, the heater fan started working intermittantly. Then it stopped entirely. I could still change the temp settings and choose between vent, floor, AC, etc. I tried replacing the fan control module (replacing the fan resistor pack has always been the fix to a non-operating fan in the past), but to no avail.

      While driving out to Las Vegas for the SEMA show, the climate control system started working in a random fashion - occasionally blowing cold air when the temp set high, blowing hot air when set cold, mixing up the dash vent for the floor, once it even turned the fan on (that was short lived). The best guess I have is the that the automatic climate control unit in the dash has gone wonky.

      After the show, I drove up to visit family in the Bay area (where I am now). This morning, I pulled a replacement from a junkyard, only to find that it didn't work at all; it did nothing when I plugged in and powered it. I brought it back and came away with the only other unit I could find there. Unfortunately, that one alos doesn't work, and now, the original one doesn't work at all anymore either. So now I have no heating/cooling function whatsoever. Or defrost, which of bigger concern to me now that winter is coming back home.

      Are the climate control modules in these fragile? Is this a common problem with a ready fix? Can I swap in the manual AC control module (it looked like the harness plugs were entirely different). Thanks.
       
    2. Support EF


      Join the Elite Explorers for $20 a year

      Explorer Forum has probably saved you that much already, and will continue to save you money as you learn how to diagnose and fix problems yourself, and learn which modifications work without having to experiment on your own. Elite Explorer members see practically no ads, add your own profile photo, upload photo attachments directly to your posts and Media Gallery, create more private Conversations, and more. Join Today. Your support is greatly appreciated.



      to hide adverts.
    3. RomeovilleIL

      RomeovilleIL Well-Known Member

      Joined:
      October 13, 2010
      Messages:
      1,064
      Likes Received:
      1
      Trophy Points:
      0
      City, State:
      Illinois
      Year and Model:
      98 LTD, 00 XLT
      Eek! I would agree the original sounds broken. Yes the electronics are somewhat fragile, but 3 bad ones in a row? Makes me wonder if maybe the issue is in your harness or GEM since its not turning on at all. Might want to grab a multi-meter or test tight to see if you have both power and ground with key turn. Once you get juice you can run the EATC diagnostic & get codes to see what is monkeyed up.

      From what I have read, swapping to manual is not a simple operation.
       
    4. Ranger Rick

      Ranger Rick Active Member

      Joined:
      December 18, 2002
      Messages:
      111
      Likes Received:
      0
      Trophy Points:
      16
      City, State:
      Rochester, NY
      Year and Model:
      '98 Mountaineer AWD
      Can someone tell me which pins on which plugs the unit should be powered by? I didn't think that it was a harness issue because when I plugged my original one back in, it would work. Not well, but enough to know it was getting power. Of course, now, it won't work anymore either...
       
    5. bobflood

      bobflood Elite Explorer

      Joined:
      May 27, 2010
      Messages:
      1,501
      Likes Received:
      4
      Trophy Points:
      48
      City, State:
      Powder Springs, GA
      Year and Model:
      1997 Eddie Bauer V8 2WD
      Great source for wiring diagrams; will tell you which pins do what:
      Auto - Online Repair Info
      http://search.ebscohost.com/
      ID: rrcc
      PW: rebsco

      Follow prompts down to Wiring Diagrams.
       
    6. Ranger Rick

      Ranger Rick Active Member

      Joined:
      December 18, 2002
      Messages:
      111
      Likes Received:
      0
      Trophy Points:
      16
      City, State:
      Rochester, NY
      Year and Model:
      '98 Mountaineer AWD
      Thanks for the information. I just got back home late last night, so I haven't had time to look through it yet. What I can add, now, is that I've tried two junkyard climate control units and neither functioned at all. My original one, however, still powers when the key is turned on, but only lights random LCD cells in the display.

      After a while, it faults out, at which point, the heat works. But it usually comes on again with the next key cycle, so the unit is clearly still being powered. That, to me, points to a fault with the unit and not the wiring, but I'm not ruling anything out.

      I will also add that the trip computer / multisystem display in the center console also stopped working at the time I tried swapping out the climate control unit. It never showed signs of issue before, but hasn't worked since. It's a minor nuisance, since it isn't critical to vehicle operation, but I liked to have the fuel range information.

      Anyway, I will look into this more later this week or on the weekend. Right now, I've got a lot of catching up to do from being away for nearly a month...
       
    7. BurnTheLight88

      BurnTheLight88 Member

      Joined:
      October 12, 2010
      Messages:
      88
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Pittsburgh, PA
      Year and Model:
      '99 Mountaineer
      search the forums, the atc units have a diagnostic mode. it is entered by holding a few buttons at once while the key is in the run position. I had to use it to reset my atc computer after i replaced the blend door actuator. this will tell you what your problem is, and when you replace it with a proper part, then you will have to enter the diagnostics again to reset the comp. it works just like the check engine light.
       
    8. SoNic67

      SoNic67 Well-Known Member

      Joined:
      January 24, 2010
      Messages:
      3,046
      Likes Received:
      2
      Trophy Points:
      48
      City, State:
      Newport News, VA
      Year and Model:
      2001 V8 (Eddie Bauer) AWD
      Automatic A/C (ETAC) has different controls than the other A/C controls. I found out that when I was trying to replace my actuator, after I did try several ones. Do yourself a favor and order one from the Ford dealer (based on the model number you have now).

      For the test mode, press "OFF" and "FLOOR" in the same time, then release and press "AUTO" (within 2 seconds). "DEFROST" clears the codes - but it won't work if the actuator is broken.
      I did have error codes 024 and 025 when a gear was broken inside the actuator itself.
       
    9. BurnTheLight88

      BurnTheLight88 Member

      Joined:
      October 12, 2010
      Messages:
      88
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Pittsburgh, PA
      Year and Model:
      '99 Mountaineer
      By the way the DTC code that I got from running this test was 025, which is Intermittent Run - time Fault for hte Blend door actuator. You might also get a DTC code of 024, which is Self-Test Fault for the blend door actuator. If there is a fault a three digit number will be displayed where the temperature is usually displayed on the ATC. Good Luck

      • lThe EATC module self-test will not detect concerns associated with data link messages like engine coolant temperature or vehicle speed signals. A NGS tester must be used to retrieve these concerns.

      • The EATC module self-test will detect concerns in the system control functions and will display hard Diagnostic Trouble Codes (DTC) in addition to intermittent diagnostic trouble codes for concerns that occur during system operation. The vehicle interior temperature should be between 4º-32ºC (40-90ºF) when performing the self-test. If the temperatures are not within the specified ranges, false in-car temperature sensor DTCs will be displayed.

      • The self-test can be initiated at any time. Normal operation of the system stops when the self-test is activated.

      • To enter the self-test, press the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The display will show a pulse tracer going around the center of the display window. The test may run as long as 30 seconds. Record all DTCs displayed.

      • If any DTCs appear during the self-test, follow the diagnostics procedure given under ACTION for each DTC given.

      • If a condition exists but no DTCs appear during the self-test, refer to the Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Improper Operation.

      • To exit self-test and retain all intermittent DTCs, push the blue (cooler) button. The control will exit self-test, retain all intermittent diagnostic trouble codes and then turn OFF (display blank).

      • To exit self-test and clear all diagnostic trouble codes, press the DEFROST button. The vacuum fluorescent display window will show 888 and all function symbols for one second. Then, the EATC control assembly will turn OFF (display blank) and all DTCs will be cleared.

      • Always exit the self-test before powering the system down (system turned OFF).

      • Intermittent DTCs will be deleted after 80 ignition switch ON cycles after the intermittent condition occurs.
       
    10. albi1cnobi1

      albi1cnobi1 Elite Mountaineer Elite Explorer

      Joined:
      December 21, 2007
      Messages:
      1,797
      Likes Received:
      0
      Trophy Points:
      46
      City, State:
      South Jersey
      Year and Model:
      99 Mountaineer V6 4x4
      Here you go. Hope this helps.
      [​IMG]

      [​IMG]

      [​IMG]

      [​IMG]

      I just converted from manual to EATC. Not that hard, going the other way would just require a little wiring and swapping the blend door actuator. It could be done.
       
    11. Ranger Rick

      Ranger Rick Active Member

      Joined:
      December 18, 2002
      Messages:
      111
      Likes Received:
      0
      Trophy Points:
      16
      City, State:
      Rochester, NY
      Year and Model:
      '98 Mountaineer AWD
      Wow, that's a lot of information to sift through. I'll poke around with it this weekend and see what I come up with. I'll probably try the self-test this afternoon though.

      One side question for the moment - does the sun load sensor that's tied into the system also switch the automatic night/day mirror into auto mode, or is that a seperate system entirely? I ask because it seems that it stopped working at the same time. I generally don't believe in coincidences with this sort of thing. Thanks.
       
    12. albi1cnobi1

      albi1cnobi1 Elite Mountaineer Elite Explorer

      Joined:
      December 21, 2007
      Messages:
      1,797
      Likes Received:
      0
      Trophy Points:
      46
      City, State:
      South Jersey
      Year and Model:
      99 Mountaineer V6 4x4
      The sun load sensor is separate. The day/nite mirror and auto light sensor is in the back of the rear view mirror.
       
    13. Ranger Rick

      Ranger Rick Active Member

      Joined:
      December 18, 2002
      Messages:
      111
      Likes Received:
      0
      Trophy Points:
      16
      City, State:
      Rochester, NY
      Year and Model:
      '98 Mountaineer AWD
      Ah, ok. Well, I did also replace the overhead compass/temp display as well recently, so maybe I upset a wiring connection up there and just didn't notice before.

      It does seem like, at 271K miles, this vehicle is mechanically very sound. However, the secondary electronics don't have the same durability. At one point or another, I've lost the function of every single component with an LCD display on it...
       
    14. Ranger Rick

      Ranger Rick Active Member

      Joined:
      December 18, 2002
      Messages:
      111
      Likes Received:
      0
      Trophy Points:
      16
      City, State:
      Rochester, NY
      Year and Model:
      '98 Mountaineer AWD
      OK, I've let this issue slide awhile, but it has become damn cold outside (13F currently)and no heat on the morning commute is rather unpleasant.

      OK, here's what I can say at the moment: for starters, the unit will not enter the self-test mode. In fact, the only buttons that generate any response at all are the red/blue temp control buttons. All they seem to do is alter which LCD cells in the display light up. That does not, however, seem to impact the actual output of the system.

      Still, it seems like the control module does something, or at least thinks it does. Typically, on start up the panel is blank. Then after 5-10 minutes, a few of the LCD cells light up, often the "PNL" and the upper left vertical part of the first digit of the temp display. But sometimes, it will start with one of the digit cells lit, and then go blank. Either way, if I push the red button, it will change and light up various other sections of the display, after a pause of maybe 30 seconds.

      So far, it seems like it always defaults to pushing air through the defrost vents. Often, it feels like it it adds enough heat to take the edge off of the chill, but not enough to drive in shirt sleeves. However, as cold as it was this morning, it wasn't able to help much. Also, the fan does occasionally kick on, but mostly I have to rely on air being pushed through by driving down the road. Typically, that's been enough to keep the winshield and side windows clear, as long as I keep moving. But that's going to be more of a problem as winter comes on.

      I've been reading about repairing the EATC units, but it seems like that repair strictly deals with sealing the vacuum lines, and my problem seems more electronic in nature. But at this point, I don't think I have anything to loose by opening the unit up and seeing if there's anything that stands out inside. I'm still searching junkyards for a functioning green chassis unit, but so far no luck...
       
    15. albi1cnobi1

      albi1cnobi1 Elite Mountaineer Elite Explorer

      Joined:
      December 21, 2007
      Messages:
      1,797
      Likes Received:
      0
      Trophy Points:
      46
      City, State:
      South Jersey
      Year and Model:
      99 Mountaineer V6 4x4
      I was just at the jy and there is a unit there that I can pull for you and ship it out if you like. I can test it in my truck first so we don't waste time and shipping for nothing. It does sound like your control unit is toast, with what you're describing. It sounds like you may have a ground problem, but tracing that in the control unit could be a nightmare so swapping it is probably the way to go. It will probably run about $40. Let me know. How are you trying to access the diagnostics? Start with the unit off, push "off" and "floor" buttons together, release and push "automatic" within 2 seconds.
       
    16. Ranger Rick

      Ranger Rick Active Member

      Joined:
      December 18, 2002
      Messages:
      111
      Likes Received:
      0
      Trophy Points:
      16
      City, State:
      Rochester, NY
      Year and Model:
      '98 Mountaineer AWD
      Thanks for the offer, I'll keep that in mind if I can't find anything locally.

      Yes, that's the procedure I've tried to access the self-test mode. However, I should qualify that it doesn't turn off anymore - the "off" button is one of the many that it ignores. I may be able to try at some point when the display is blank, that might essentially be off. But I don't think the unit is capable of self-diagnosing its own problems, only problems that exist in the EATC system as a larger whole.

      Interesting thought about the grounding, if I can ID which pin on the connector is ground, I may be able to jumper it to ground as a test.

      What I can't figure out is this (and I may not have been clear on the point previously): before I removed the head unit, it appeared to operate fine. The only sign of trouble was the intermittantly operating fan, which I thought was a fan controller issue (but isn't). I could set the temperature, I could choose the vent setting, I could turn the rear fan on - which was nice, since it helped make up for the lack of front fan. I cannot say, however, that the unit was actually directing air where I set it. Without the fan running, it was tough to tell where it was coming out. But at least the display would indicate "floor" or "pnl", etc. in response to pushing the said button.

      All of that changed when I removed, and then subsequently reinstalled, the controller head unit. As far as I know, I did nothing but unplug and then replug the harness and lines, unbolt, and then refasten the unit to the dash. I recall having some difficulty getting the wiring plugs to give up, but other than that, there were no issues in removing and reinstalling the unit. And yet, in doing so, somehow, the controller's behavior changed distinctly from what it was to what I've described in a previous post - erratic. So that confuses me as well, but at least seems to emphasize that the EATC head unit is the fault here, rather than a hardware issue...
       
    17. deezyp

      deezyp New Member

      Joined:
      January 22, 2012
      Messages:
      3
      Likes Received:
      0
      Trophy Points:
      1
      City, State:
      Seattle, WA
      Year and Model:
      1996 explorer limited
      do you guys have an update for this problem? I'm having a similar one....my EATC works fine, did the self test a few times and got '888' which i read in another thread is a pass..but all i'm getting is COLD AIR. I have a '96 explorer limited if it helps any. I also had a navigator with the EATC and it did the same thing, but it was coupled with an erratic temp gauge...ended being the thermostat but it never again had the efficient heater it once had. I hope this isn't the same way.
       
    18. Cranmaro99

      Cranmaro99 Active Member

      Joined:
      August 31, 2011
      Messages:
      309
      Likes Received:
      0
      Trophy Points:
      0
      Year and Model:
      2001 Explorer 5.0 AWD
      Probably bad blend door or actuator. Very common and doesn't seem like it's your ETAC being the issue.
       
    19. CDW6212R

      CDW6212R Elite Explorer

      Joined:
      June 17, 2004
      Messages:
      14,401
      Media:
      3
      Albums:
      1
      Likes Received:
      26
      Trophy Points:
      68
      City, State:
      Knoxville, TN
      Year and Model:
      98 Mountaineer AWD
      I also have a 98 Mountaineer with EATC, that heats the air in any position or temperature.

      FYI, these electronic devices have certain capacitors inside of them which go bad over time. I'd search for repair places which deal with the repairs, mentioning the capacitors. I have a Mark VII that has several devices that need that kind of rebuilding. It generally costs $100 for rebuilding each device in the Mark VII, the trip computer, EATC, overhead console(like Explorer), and the radios. When rebuilt they typically work and last as long as a new part.
       
    20. drbenz

      drbenz Active Member

      Joined:
      July 23, 2011
      Messages:
      194
      Likes Received:
      0
      Trophy Points:
      16
      City, State:
      High Point, NC
      Year and Model:
      2000 EB 5.0
      Aside from the possibility of loose pin connections at the eatc unit, there is the chance you have poor connection at a fuse, it would be unusual for several things to go out at the same time otherwise.
       
    21. neff's 99 5.0

      neff's 99 5.0 New Member

      Joined:
      February 12, 2012
      Messages:
      1
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      Pace, FL
      Year and Model:
      99 5.0 explorer
      How do u run the eatc diagnostic?
       
    22. albi1cnobi1

      albi1cnobi1 Elite Mountaineer Elite Explorer

      Joined:
      December 21, 2007
      Messages:
      1,797
      Likes Received:
      0
      Trophy Points:
      46
      City, State:
      South Jersey
      Year and Model:
      99 Mountaineer V6 4x4
      Press and hold the "Off" button and then press the "Floor" button. Release those and quickly press the "Automatic" button. That gets you into the diagnostics. When you're all done make sure to press the "Defrost" button to clear the unit from test mode.
       
    23. thevichas

      thevichas New Member

      Joined:
      May 14, 2012
      Messages:
      2
      Likes Received:
      0
      Trophy Points:
      0
      City, State:
      ohio
      Year and Model:
      1997 Explorer E.B.
      diagnostic info ?

      • If any DTCs appear during the self-test, follow the diagnostics procedure given under ACTION for each DTC given.

      • If a condition exists but no DTCs appear during the self-test, refer to the Symptom Chart Condition: The EATC System Is Inoperative, Intermittent or Improper Operation.

      Where do i find this information?
       
    24. Ranger Rick

      Ranger Rick Active Member

      Joined:
      December 18, 2002
      Messages:
      111
      Likes Received:
      0
      Trophy Points:
      16
      City, State:
      Rochester, NY
      Year and Model:
      '98 Mountaineer AWD
      It's been a while since I posted an update on this, but there hasn't been much to update. At least not in terms of resolution.

      I spoke with a guy yesterday that runs a shop locally that specializes in AC service. He seemed surprised that the head unit did nothing at all, coupled with the fact that the replacement unit also did nothing. He said that it would likely take multiple hours of diagnostic work to identify the issue, with a shop rate $90/hr. He seemed to hint around that he wouldn't think that the cost was justified for the vehicle.

      Anyway, my last option, it would seem, is to pull the parts needed to convert the system to a basic manual-AC that most of these vehicles have. I think I'll be off to the junkyard in the morning. The info that was posted earlier here regarding swapping in the EATC system ought to serve as a reasonable guide for what to do in reverse...
       
    25. RomeovilleIL

      RomeovilleIL Well-Known Member

      Joined:
      October 13, 2010
      Messages:
      1,064
      Likes Received:
      1
      Trophy Points:
      0
      City, State:
      Illinois
      Year and Model:
      98 LTD, 00 XLT
      Rereading the older posts, I get the feeling you really do have a wiring problem. The issue of suddenly getting no responses after plugging/unplugging and having multiple head units inoperable seems to pretty much nail that one down. However, my guess would be not that a power wire is bad but instead one or more of the grounds between the plug and the gem. Rather than trying to chase through that mess of wires, at this point I would head to a yard and pull a wire set from another vehicle with working EATC.
       
    26. Ranger Rick

      Ranger Rick Active Member

      Joined:
      December 18, 2002
      Messages:
      111
      Likes Received:
      0
      Trophy Points:
      16
      City, State:
      Rochester, NY
      Year and Model:
      '98 Mountaineer AWD
      I'm thinking along those line too. To sum up what I've experienced: the EATC issue started with intermittant fan operation. I replaced the fan controller, to no avail. So I swapped head units, and in so doing, no head unit since plugged in has operated correctly. However, it is powered, at least in part. The lights come on, and after about 10 minutes of operation, random bits of the LCD light up. This is true for when I replaced the head unit, and for when I put the original back in again. The random lighting is the extent of what it does; at this point it will not enter diagnostic mode either, nor will the rear fan operate anymore.

      To be clear, the original at least outwardly appeared to function correctly before pulling it out, even though I didn't have complete system operation. Also of note, prior to swapping the EATC, the message center worked fine. After, not at all. I know they're tied together, so that is suggestive as well.

      So, I agree, that does seem to suggest that there's a issue in how the EATC head unit was connected. Or, at least, with the wiring that it plugs into and it was disturbed when I messed with it. Maybe the best fix is to find a replacement for the dash harness, or the EATC portion. The trouble is that Explorers with EATC don't commonly appear in the junkyards. There are too few of them with the option, it would seem. I don't particularlly want to give up on the system, but I'm not sure how many choices I have.
       

    Share This Page









    We Support Our Troops!