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So the issue started 2 days ago out of the blue - I have it on cold and the air suddenly got warmer. I thought that was strange, so I set the slider to the right onto heat, and then moved it back to cold - air went back to being cold.
Then yesterday, I tried testing it out again except this time, after I slid it over to heat and slid it back to cool, the air kept blowing hot. This was very annoying, as you can imagine in the Texas heat. I had the car off for about 1 to 2 hours while I was taking care of some errands, and when I got back, the air magically became cold again on the cold setting.
Then tonight, I decided to test it out one more time, and now it seems to be stuck on hot air.
I'm not sure if the AC is broken because I can "hear" it turn on when I push the button? But the air is still blowing hot, even though it's set on cold. Also, if the AC was broken, the air would be a little cooler when on the cold setting, as opposed to just remaining completely hot regardless of where I set it.
Any ideas on how to diagnose this? Something mechanical broken inside the manual climate control adjuster?
Have an update: I checked the big aluminum AC line (with the AC turned on), its freezing cold as it should be.
So, I think the AC is working - sounds like its something mechanical that isn't "shutting off" the hot air when I move the climate control slider to cold?
I found an old thread that may be the issue I have - I can't tell as of now, I'm gonna take it into a local shop tomorrow morning I think to have them take a look.
The 1994 3rd gen Maxima was the last Maxima to use a water c o c k. Engine coolant flows through the heater core all the time now. Temperature regulation is accomplished by regulating the amount of air that goes through the heater core.
So Nissan has the "air mix door" that is moved by the "air mix door motor". If the temperature of the air doesn't change, then get down in the passenger side foot well, remove the plastic trim piece from the end of the ECU. Then turn the ignition switch to "ON" (you don't have to start the car) and change the temperature setting back and forth between full hot and full cold. If the air mix door motor is working, you will see the arm on the air mix door motor move when you change the temperature setting.
The 1994 3rd gen Maxima was the last Maxima to use a water c o c k. Engine coolant flows through the heater core all the time now. Temperature regulation is accomplished by regulating the amount of air that goes through the heater core.
So Nissan has the "air mix door" that is moved by the "air mix door motor". If the temperature of the air doesn't change, then get down in the passenger side foot well, remove the plastic trim piece from the end of the ECU. Then turn the ignition switch to "ON" (you don't have to start the car) and change the temperature setting back and forth between full hot and full cold. If the air mix door motor is working, you will see the arm on the air mix door motor move when you change the temperature setting.
If not...
]
Awesome, thanks for the detailed instruction. I will check it out tomorrow morning. Just a quick question - the passenger side foot well plastic trim piece - it comes off if I just yank it right? No screws or any part of the dash need to be removed first (I hope not!)?
Also, if it turns out that the air mix door is stuck, is it expensive to get it replaced? And can I just manually push it onto the cold side (however that would work...) for now since it's still hot in Texas? If it is expensive, I don't think I'm gonna bother replacing it because I don't intend on keeping this car for much longer if I can help it.
The plastic trim panel is maybe the size of a postcard and doesn't use any screws. It has 2 plastic push-in buttons to hold it on, so you should be able to pull it off by hand. But sometimes those buttons won't co-operate and you have to pry them out with a screwdriver.
If the motor doesn't move, you would have to disconnect the motor from the air mix door arm. You can't move the motor by hand. Then you would need to somehow prop the air mix door in what ever position you want it to be in. The motor is what holds it from moving.
Taking it to a shop to get it fixed will cost $200 to $300, maybe more. The motor is a Nissan only part (part number 27732-40U00) and lists for $98. Then you have the mark up the shop will charge on the part and the installation labor and I really don't know how much the labor would be.
The plastic trim panel is maybe the size of a postcard and doesn't use any screws. It has 2 plastic push-in buttons to hold it on, so you should be able to pull it off by hand. But sometimes those buttons won't co-operate and you have to pry them out with a screwdriver.
If the motor doesn't move, you would have to disconnect the motor from the air mix door arm. You can't move the motor by hand. Then you would need to somehow prop the air mix door in what ever position you want it to be in. The motor is what holds it from moving.
Taking it to a shop to get it fixed will cost $200 to $300, maybe more. The motor is a Nissan only part (part number 27732-40U00) and lists for $98. Then you have the mark up the shop will charge on the part and the installation labor and I really don't know how much the labor would be.
How hard would it be to replace the part on my own?
The air mix door motor is right above the ECU and is held on by 3 Phillips head screws. You need to remove the ECU to get at the screws with an offset screwdriver. The ECU is screwed down to the floor, but removing the ECU is not an easy task because the wire harness is in your way.
However, while the motor has a high likelihood of being the problem, the heater controls in the dash could be the problem also. You (or whomever is going to work on this) needs to follow the troubleshooting guide in the service manual to determine what part is defective. See page 51 in the link below for the troubleshooting guide.
Ok, so using your picture from earlier as a guide, I took off the plastic cover and was able to identify the mix door operating arm. By the way, as someone who is 6'2 205lbs, it is ridiculously difficult to crouch down into the passenger side foot area to get a looking there - ugh. That was painful lol.
Anyways, you were right - I kept ignition on the ON position, changed the setting from cold to heat and back, the operating arm is just stuck. No movement.
So, from this, is it pretty certain its the motor? Or could it still be the heater controls as you mentioned? The only way to know for sure is by following the instructions in that page in the FSM?
I have a meeting later today and can't risk waiting at the car shop today because there are several cars ahead of me, but I plan to take it in first thing tomorrow morning when the shop opens. I'll ask them to check out the tests on the FSM.
To remove the ECU, you will want to take the stereo out, and the lower air cowl out (the air blows through the lower air cowl when set thru HVAC). You then can access the two M6 bolts.
That's the easy part. The hard part is to move the ECU laterally towards the passenger foot well. There is a single metal clip that holds the ECU in it's current position. It took me 1 hour to figure out how to move the ECU.
ef9, how much do you think the re-sale value of the car would drop if I didn't get around to fixing this issue? The AC works, but not for practical purposes. I just got a 2014 Maxima S and am looking to re-sell this one, just not sure how practical it is to try and fix it. I bought the part, but not sure it's worth shelling out like $300 for labor at a shop if I can only get a $1000-$1500 for the whole car itself (186,500 miles).
I *could* try to fix it myself, but I have no idea where to start - I remember taking apart my dash years ago to install a Pioneer CD/iPod stereo interface, and those instructions were great - is there anywhere online that would show how I can do the repair for this? (including taking apart the dash, the lower air cowl, etc.)
I'm not sure what the value would be. If you lived somewhere the temperature rarely changes, then that person wouldn't care if it's stuck in a certain position. Here in Hawaii, it's always warm. Some people don't ever use the heater in their car.
I'm not sure what the value would be. If you lived somewhere the temperature rarely changes, then that person wouldn't care if it's stuck in a certain position. Here in Hawaii, it's always warm. Some people don't ever use the heater in their car.
Good luck.
I'm in north Texas - summers are very hot. Without functioning cold air, it would be a mess.
ef9 or Dennis, do you know if removing the glove compartment would be an alternate way to get to and replace the air mix door?
The air mix door motor is right above the ECU and is held on by 3 Phillips head screws. You need to remove the ECU to get at the screws with an offset screwdriver. The ECU is screwed down to the floor, but removing the ECU is not an easy task because the wire harness is in your way.
However, while the motor has a high likelihood of being the problem, the heater controls in the dash could be the problem also. You (or whomever is going to work on this) needs to follow the troubleshooting guide in the service manual to determine what part is defective. See page 51 in the link below for the troubleshooting guide.
Referring to page 51, which plug is the air mix door connector shown in the first step? Is this the wire that connects to the hot/cold dashboard setting?
Referring to page 51, which plug is the air mix door connector shown in the first step? Is this the wire that connects to the hot/cold dashboard setting?
Box A or step A is referring to the wire harness connector that plugs into the air mix door motor. The manual tells you to unplug the wire harness from the motor and check for voltage on the wire in the plug (plastic connector). You put the voltmeter probe in the side that the wires are going in, not on the side that plugs into the motor.
The problem you might have doing this is that the voltmeter probe may be too thick to get in and be able to touch the metal pin connector. I use a straight pin, those things they use in dress shirts when you buy one that is all folded up in a package. You could probably use a paper clip also.
Steps A & B are having to check that you are getting power (12 volts) and ground to the motor. Step C is having you check that the wires between the motor and control unit are not broken.
Step D on the next page (52) has you checking the control unit for being able to create the signal to operate the motor.
So if you get the proper voltage in step D, then the motor is bad. If you do not get the correct voltage, then the control unit is bad.
So the issue started 2 days ago out of the blue - I have it on cold and the air suddenly got warmer. I thought that was strange, so I set the slider to the right onto heat, and then moved it back to cold - air went back to being cold.
Then yesterday, I tried testing it out again except this time, after I slid it over to heat and slid it back to cool, the air kept blowing hot. This was very annoying, as you can imagine in the Texas heat. I had the car off for about 1 to 2 hours while I was taking care of some errands, and when I got back, the air magically became cold again on the cold setting.
Then tonight, I decided to test it out one more time, and now it seems to be stuck on hot air.
I'm not sure if the AC is broken because I can "hear" it turn on when I push the button? But the air is still blowing hot, even though it's set on cold. Also, if the AC was broken, the air would be a little cooler when on the cold setting, as opposed to just remaining completely hot regardless of where I set it.
Any ideas on how to diagnose this? Something mechanical broken inside the manual climate control adjuster?
Thanks!
☆☆☆☆☆☆
I Fixed This On My My Ole '96 Max... well, MY Version of "FIXED", At Least!
There was an ACTUATOR With The ARMS STUCK (In HOT Position)...
Probably Needed New Actuator Motor ?!?...
& the Word "Probably" Is Why I Said That It Is MY Version Of "FIXED" ! However, I Just (Carefully) Pried The Arms Apart & Left It At That!
For Multiple Reasons, I Stopped When & Where I Did!
Other Than The INCONVENIENCE Of Having To MANUALLY Move The Arm Accordingly Whenever I Want Hot Air Or Cold Air, I'd Say It's Pretty Well Done!
Oh Wait... I Also Topped It Off By Stuffing A FIRM Piece of FOAM (From The Crumbling Old Seats Which I Also "FIXED" Via SEAT COVERS! LOL) Up Into The Crevice To Hold Arms In Place!
YEAH, ANOTHER INCONVENIENCE Having To Do That Every Time You Need To ADJUST The Arms But...
It's Been A GREAT RESOLUTION For ME Since I No Longer Have To BURN UP!
By The Way, The PROBLEMATIC Actuator Arms On MY Max Were On Passenger Side & Above ECU... To The Right of Ashtray Column Area!
GOOD LUCK!!!!!!
I Had EXACT Same Issue... I Looked H ⬆️ & L ⬇️ & In The Middle, etc... & Well, Basically Every LEVEL In Between (& Then Some)... On the Internet (& In The Vehicle) For A RESOLUTION To This MOST... "💩Y" Problem!!!
One Which Became Increasingly Imperative To Solve... Especially When I Reached 🔥'TEXASS' 🥵 From 🧊"UP⬆️NORTH"🥶... Until... FINALLY... ONE DAY... SOMEHOW... SOME WAY 🤷🏼... NO THANKS To ANYTHING
I FOUND ON The WEB... I FIGURED IT OUT MY 🤬 SELF!!!
After Much Trial & ERROR, Sheer DESPERATION, & Your Basic Good Ol' Fashioned STUBBORNNESS...
"I GOT IT, BY GEORGE!" ME, MYSELF, & I... (& GEORGE?!?)
CULPRIT:
IT Did, In Fact, Turn Out To Be:
THE ACTUATOR ARM BEING STUCK IN THE
(Clearly) ♨️HOT🌶️ POSITION!!!!!!
LOCATION:
THAT PARTICULAR ARM Is Behind The Center Dash Console (The Area Containing Climate Controls, Stereo System, & Ashtrays)... Located ~ 1-2" Above the ECU... Slightly To The Right of It's Middle... The Side Closest To The Firewall... Most Easily Reachable Via Passenger Side Floorboard Area... Below & To The Left Of Glove Compartment.
RESOLUTION/FIX:
Once AGAIN... That Depends On Your DEFINITION Of "FIX"!
MY HYPOTHESIS... EDUCATED GUESS... Would Be To REPLACE The MOTOR For Said Actuator Arm... At Least ForAn APPROPRIATE "PERMANENT" FIX!!!
HOWEVER, Since I Only Paid $500 For This Car Which I Had ORIGINALLY PLANNED To Just Drive It 6 Hours To An Airport Then LITERALLY... Just GIVE IT AWAY TO SOME NEEDY YET DESERVING STRANGER... I Was Not Thinking That It Was Worth It To Sink Basically ANY $ Into It... IF POSSIBLE!
Therefore, At The Time, I Just FORCEFULLY RELEASED THE ARM (It's Been A While So I'm Not Sure Exactly HOW Did It But I Didn't BREAK ANYTHING... 🤔 Actually, I Really Don't Know HOW, Though!) As A Sort Of "QUASI-FIX"!!! From That Point On, It's Simply Been A Matter Of It Being A MANUAL TASK For Every Time I Need To CHANGE It From HEAT To A/C... Which Is Nothing More Than SLIGHTLY INCONVENIENT... UNLESS You Are In The 🔥HELL•EDO👿... I Mean, LAREDO Area In 🔥'TEXASS' 🥵... Like STUCK There For > 2 YEARS, PERHAPS!?? I'm Just Saying!!!
Anyway... The CLIMATE HERE LITERALLY DOES, IN FACT, REQUIRE IT TO BE CHANGED BACK & FORTH BETWEEN THE HEATER & THE A/C... Depending On The "SEASON" (If You Will), MULTIPLE TIMES PER DAY!!! UNFORTUNATELY, NOW Is THAT Season &... YES, I AM SADLY STILL STUCK HERE... BUT... I AM LEAVING WEDNESDAY For MEXICO CITY... WITH OR WITHOUT MY NOW "PRECIOUS, BEAT UP, STRUGGLING LITTLE "MaxiNeese"🤞 HOPEFULLY... "WITH"!!!!!!
CONCLUSION:
SO MUCH FOR "TEMPORARY FIXES" DUE TO MY PLANS OF GIVING THE OLE GIRL AWAY... ESPECIALLY SINCE I JUST WENT INTO DEBT TODAY FOR 4 NEW TIRES & 2 NEW RIMS...
~ $600... JUST AFTER Paying $200-ish For Insurance & Updated Registration (Late Fees & All)... Not To Mention GOD KNOWS HOW MUCH I'll Have To Pay For The 3-In-1 TICKET The Kind 👮♂️Police 🚨 Officer Just Bestowed Upon Me The Other Day (Hence The Registration Payment)... The $250 + Last Month For New EXHAUST PIPES After Mine FELL YO THE GROUND... & The $250 I Will Be Paying To CROSS THE BORDER In A Few Days... HOPEFULLY...
Then I'm Going To 🙏 PRAY That She Makes It Since I Still Have A MYSTERIOUS COOLANT LEAK That Nobody Wanted To Touch!!!
SO... YEAH... AGAIN I SAY... SO MUCH FOR THE "TEMPORARY" FIXES & GETTING RID OF HER!
HOW DID SHE GROW ON ME LIKE THIS??????
ONLY OTHER "MAXI-LOVIN' OWNERS" COULD POSSIBLY KNOW!!!!!!
09-30-2015, 06:59 PM
