AutoClimate Control
Nissan readings.

AMBIENT DATA:
Ambient Humidity: 39%
Ambient Tempurature: 87 F

VEHICLE DATA:
Red Vent Temp: 82 F
Blue Vent Temp: 51 F
High Side Maximum: 183 psi
Low Side Minimum: 28 psi
Charge Weight: 1.5lbs

Well here I am, still having problems with my A/C in my car.
Replaced OEM Compressor, OEM Expansion valve, Evaporator and dryer.

First tiem I had it at nissan, they blamed the Intercooler. Well I agreed to get it back there a second time to have the system completely evacuated and charged. To make sure there isnt too much oil in the system.

Well brought it to nissan for a second time to have them evacuate it and recharge with all fresh oil and refrigerant, and they say they measured all of the system numbers and they are all up to spec and they are not going to evacuate and recharger. They now want to take the entire dash out and check the a/c door in the dash.

The A/C is cold but not Cold Cold. Listen, I am sweating inside the vehicle. Its rediculous. Any chance that one of the mixing doors is stuck open and letting outside air in from outside ? If so, anyone ever fix this, and does the entire dash come off to do this ?

I need an a/c specialist for sure.

Thanks guys.

 

fwiw an ac can only make about a 20 degree change in temp from outsied to interior. but i'm sure there is a problem with your a/c. good luck...and i would check the 'mixin door'

 

FMIC is not the problem. There are guys with my same setup in Texas, Florida with Ice cold air.

I kinda think its too much oil in the system, and maybe a bit clogged the Expansion valve. Nissan seems to not believe this cause the pressures are fine. idk.

thanks

 

Are you sure about that??? That would mean that today it was 80 degrees in my car (100 degrees outside) during my 1.5 hour journey to work training. Bzzzzzz. It was a nice and chilly 68 degrees in my Max. Never ever did I feel sweaty. FWIW, I have Auto Climate Control so I knew the target temperature and the fan speed went to the lowest setting once the temp was achieved.

Matty, same thing happened to my GF's civic. One the AC stop blowing cold and was then repaired by an AC specialist, then HONDA because we were still un-satisfied, it was never the same chilliness as it was before. Good luck with your dilemma.

 

I had an auto climate controller thingy that I took apart one time and the temperature probe was covered in dirt and dust, just throwing it out there that you might try to swap the unit with someone else with auto and see if there is a difference. You can try to clean the temp probe and see if that helps before gutting out the front of the car.

 

my Stock AC is exactly opposite its to freakn cold, everyone who rides in it says same thing, even at the 1st setting its freezing, 2nd setting was the highest i ever had to put it to for NYC 100degree humidity

 

The A/C self diagnostic will check the doors, code 30 means all door are ok, page HA-75 (MY97 FSM).

 

30 does come up

 

and code 20 comes up for sensors?

 

Has the A/C ever been charged by anyone but the dealer?

Kruso

 

I get a flashing 23 and 25 car was cold and in sunlight (overcast but over 60w)

-matt

 

That might have seemed like an ignorant question but all the dealer will check for is the amt of pressure inside the system not the freon/ refrigerant concentration within it. The system has to be vacuumed prior to refilling with the new refrigerant. Was that ever done?

Kruso

 

Yes. The end of last season but there could have been way too much oil in the compressor and that could have made a problem for sure

-matt

 

Shine a light on the Sun Load Sensor, rerun the test and see if code 25 goes away.

Not quite sure what a code 23 is. You have to find a A/C guru about this.

Open the A/C controller and see if you can find solder joint cracks.

 

When I put oil in my new compressor (dry), I have to turn the shaft to get all the oil in.

 

Wheres the A/C controller ??

 

Two parts, the sensors get plugged into the display unit. The doors and things are driven by the amplifier box just above the ECM.

 

Cars sitting in the sun, 25 went away. 23 is still there

Checked 5 again and the temps are 88 and 110. 3 still comes up 30.

-matt

 

Not sure where that is.

 

Just below the radio behind the ashtray.

 

Code 23 may be the "intake" sensor for some years. This is located just after the evaporator in the airflow. Thermistor sensors are basically low R value for high temp and high R value for low temp. So you can drip this device in hot and cold water and see if the resistance change value. There may be a R value vs temp table in the FSM for this sensor.

Also, if you manually set the fan speed to high, does it get cold faster? If it doesn't get cold even with fan set at high, the problem is still on the thermal side (compressor, evaporator, condenser, expansion valve, heater core, etc).

 

Just drove around with the car.

First got in, sunny out, got 20 to pop up on the 2 setting. 30 is still coming up, 41-46 all cycle through the different fans, and the 5 setting for temps was 88 and 110.

Drove around, cloudy out now, got 25 and the temps at the 5 diagnosis were 82 and 76.

Thanks for all your help
-matt

 

I have similar problems and still haven't found a solution.

 

For step 51, there should be 3 temperatures; Ambient (nose), In-vehicle (dash) and Input (air box) sensor on page HA-77 (MY98 FSM). Your reading was like:
Sensors: Amb, InV, Input
Startup 88, 110, ?
Driving 82, 76, ?

Are you missing the Input Sensor? This was attached to the Evaporator on the down stream side. It looks like a thick coated wire with a connector attached. The connector is on the front of the airbox (facing the passenger). and it enters the airbox thru an oval hole.

If you are missing this sensor, then controller view it as high (infinite) R value. Which the controller interprete the temperature of the evaporator to be low.

 

No, for step 51 I only have two temp readings. If I uplug that sensor, under the dash pointing towards the pass, oval opening, thick wire, I still get two temp readings readings. not 3

I have a 96

-matt

 

Find a MY96 FSM and find out code 23 as well as the code 51 temperature readings.

 

1: Conduct self-diagnosis STEP 2 under sun shine.
When conducting indoors, direct light (more then 60W) at sunload sensor or Code no. 25 will indicate despite the fact that the sunload sensor is functioning properly.
2: Conduct self-diagnosis STEP 2 after warming up engine.
When engine coolant tempurature is low, code 23 will somtimes appear even when thermal transmitter is functioning.

Display - 51
-----> Press (DEF) Switch.

Tempurature detected by each sensor
indicated on display------------------------> Ambient sensor
-------------------------------------------> In-vehicle sensor

 

Where are you getting this code from? The main computer? Don't understand, please explain - I also have similar problems with my AC and I already changed the automatic climate control unit.

 

Hold down the off botton shortly after turning the car on. Then press up on the heat and it will bring you to 20 30 40 50, all different ways to diagnosis problems with the doors, sensors and whatnot

-matt

 

Code 23 doesn't show up in the MY98 FSM and code 51 shows three temperatures. So you need a MY96 FSM to tell what is happening. You may want to go ahead and pull the Intake Sensor and check the R value vs temperature table.

Does it get cold if you manually set the fan to high?

 

98-99 Have a more advance auto climate system.

Matty's problem is not electrical...

 

Since he has practically all new thermal side components, compressor, expansion valve, evaporator, and dealer has charged the system; this likely will be the cabin side system issue.

If MY96 controller has no diagnostic test for the Intake sensor, then Matty has to test this device manually.

Beyond that, there is a procedure to calibrate the cooling downward called Temperature setting trimmer, MY98 FSM page HA-79. It can adjust the cooling downward by 6 deg F.

 

I am assuming there is too much oil in it. He said after like 30 min it starts to get colder

 

When Matty charged it the first time, he used PAG100 oil. I assume the dealer recharged it with PAG46 oil but may not have drained the system. So there may still be PAG100 oil mixed it. But no one knows the real effect of PAG100 in this compressor.

 

All of the nissan dealerships, and all of the A/C techs around my area said there shouldnt be any ill effects using PAG100 in the compressor. Even David Burnettes guy who has been working on a/c systems for over 20 years, nissan tech, said PAG100 is fine in the compressor.

Nissan didnt evacuate the system and recharge. They only read the values on the machine and called it a day. According to a few people, even with the values correct, there might still be too much oil in the system. Nissan just doesnt want to dig any deaper.

-matt

 

In that case, reclaim and store the freon, drain the compressor, refill it and put the freon back in. There is a procedure for that in the FSM. Get new o-rings when you take the compressor off.

 

You would recommend the compressor coming off the car, or will all the oil come out when they evacuate the system a few times.

-matt

 

After they reclaim the freon into a holding tank, they can drain the compressor with the plug on the bottom. Normally you would fill the compressor from the top but they may be able to add oil from the low pressure port without removing the compressor.

 

Could some nice person point me to a link for the MY96 FSM?

 

Update.

Alright brought the car to a local place by me and they evacuated the system, and there was only .5lb of freon in the system, from when Nissan tested it. That means nissan totally didnt do anything on the car.

Well I got it back from after being being put on vacuum for 1/2 hour and charged up and its still not all that good. Set at 65, full fan, really isnt pumping cold but the line going into the car is Freezing Cold!!

Is is possible that heat is mixing with the air ?? Where do I go from here ?

I tested the auto climate again, and still 30 is showing up. I took some dash peices out and started looking at the door and the armatures for the doors are moving freely. How do I know there is no hot air mixing ??

-matt