Ok, my issue is that my Air Conditioning works fine at 65 degrees but when I but it to 66 or above, it is the same hot temperature. Any one have any ideas?

 

Manual or auto?

 

The duct behind the dash that send the cabin air to the temperature sensor may drop off.
Did you recently do any audio work of the car?

 

Got to be auto being he can dial in a temp.

Could be a sensor gone bad, there's a diagnostic mode - pmohr got that info for him?

 

Err, yea...don't know what I was thinking there.

First you need to do the diagnosis:


Then check the codes:

 

i checked it out and pulled codes 21 and 25.
Is this what is causing my issues?

 

I can say definitely yes on the ambient sensor because I inadvertantly killed mine off a couple years ago. Found a Negative Temperature Coefficient (NTC) thermistor in Digi-Key for less than a couple bucks and it's been working fine ever since. Of course a junkyard is another good source but they may want to sell you the whole control. A dealer may offer just the sensor, I seem to remember it was all plug the actual thermistor is about half the size of a grain of rice.

 

Indeed, it could very well be the ambient air temp sensor.

Messed around under the hood lately? Check the connection to it, and give it a test per the FSM.

 

Interesting that you pointed out the location of the sensor pmohr because it made me realize that it was the the in-vehicle sensor that I fried. The results were as I stated however. So, logically, it seems that the loss of any of the sensors results in similar symptoms.
I have never done surgery on the ambient sensor but I am reasonably confident that with the proper diagnostics info that one could, in fact, repair the old one with the appropriate thermistor thus saving one the $50 bucks they seem to be asking for that sensor.

 

i have a similar situation. ill have my a/c off and the air running thru my feet is scortching hot.the mechanic i went to said it was some type of amplyfier behind the center dash.he also said the part from nissan is $1500.for a quick fix he tried switching a door behind the dash so the hot air wouldnt blow but that lasted a couple days. jus lookin for some input before i go look at scrap yards for the part.

 

How about you keep it at 65 and stop whining?

 

bc i have no cold air at all and its already 100 degrees here

 

Considering he specifically mentioned 65 degrees, he likely wasn't talking to you.

So now you don't have AC? You said nothing about that in your post. If you want help, all the information, especially like that, is necessary.

 

its an auto.i havent done anything that would directly affect the a/c in anyway. the only person whos looked at it is my mechanic who tried fixing it but failed. the a/c works fine but its the same temp no matter what i select...so it blows hot air if its on and hot air comes through if its off
i dont have a code reader and no CELs have come up

 

I had an 86 300zx that had a similar problem. I believe all the vent doors and such were vacuum actuated, so when the car was under high load all the leaky vac lines would let go and I would get a gush of hot air and cruise control would shut off. But I bet these cars don't have vacuum operated everything now.

 

So how is it that the 'AC works fine' but it only blows hot air? That's a complete contradiction, it's one or the other.

 

im trying to say when i turn the a/c on it says its at 65 degrees but hot air is coming out

 

If I may, he means at 65 he can get cold air out but any other number it switches to hot air.
The answer you need is in the posts above, it is the ambient air sensor or perhaps the connection to it. It's really a rather unsophisticated little part when you come right down to it. If I remember correctly, the higher the temperature, the lower the resistance and thats how the system knows what the temperature is.

 

I got a very similar situation as well. When I'm idleing I get nice cold air but when I start driving after a few minutes the air seems to get kinda humid and gets warm. It also seems to be dependend on the temperature outside as when I was in cali and it was not too hot outside the air was working fine even while driving, but then when I got back to AZ its only cold when im idling and then start driving it gets warm. I also think the compressor is turning off and back on.

 

cruise control is vacuum operated... and how to u think the brake booster works?

 

press the recirculate button it will stop.. both of my cars (maxima and impala) do that...

 

tried it and it nothing happend

 

there is a flap that is supposed to close when u press that button... do this..

have the car on then stick your head right by the gas pedal and press that button again... u should hear something close

 

I have auto. It does this to me too. Just turn it on drop the temp on the screen from 85 to 65. Your problem will be solved. The temp you previously had it set at is stored even when it is off. So if you set it to 65 then turn it off you wont feel the hot air anymore. And selecting the recirculation button should work too if it is 100 outside. Its suppose to close the vents from receiving outside air if yours doesnt you may want to look into that.

 

Ive been having A/C problems every year and here again, still doesnt working properly. Brand new everything in the car and still not COLD COLD like it should be.

What would a 23 mean on my screen when I run the diagnosis ?

-matt

 

Thermal transmitter.

Check the diagnosis on HA-99.

 

Where is that ??

Just took the car out for a ride...a/c gets cool, but not that extra shot of COLD it should be like...

Ran the test when I got back, now im getting -26, and quickly goes to 20...whats PBR ??

 

PBR is 'Potentio Balance Resistor' according to HA-117.

Also note that code 23 can show up if the engine isn't at operating temp. Apparently the 'thermal transmitter' is just the temp sensor for the gauge cluster.

 

Yea...no more 23...but I am getting a -26 that flashes up, then goes to 20

-matt

 

Where is the "Potentio Balance Resistor" ??

 

Built into the air mix door motor, as you can see on HA-89...

Diagnostics are on HA-101.

 

I dont have these in my computer any more...any way you can post up pics

-matt

 

Link's in my sig

Nothing much to really see, the air mix door motor is about directly behind the stereo, in that center stack somewhere.

 

What M number is it ??

 

For the connnector? M49.

 

I read that entire thing...the PBR is the actual cold air/hot air mix door ??

 

No, it's built into the air mix door motor. Failure means replacing the whole motor for it.

 

So me getting that code pretty much sais why I am not getting air that is cold. I have been battleing this a/c system since last year and gave up on it due to the weather last year. Now that its hot again, im back to troubleshooting..

That motor isnt working ?? not closing ??

 

Have you done the PBR diagnostics?

 

Not yet..I have to get my volt meter and find those connectors