Help with AC please

[Michigan NSX]

OK - I have a problem with my AC. I jusat had the evaporator replaced as well as the long aluminum pipes running under the car and had the system converted to R134 and charged. Here is the problem.

If I put the AC on auto (the left button on the climate control) the system seems to work OK. It is very cold when set to 60 but if I put it up to 61 degrees it doesn't seem near as cold. Is this right? I can leive with this if it is common. HEre is the REAL problem:

If I press the MODE buttons (to direct the air onto my face or feet) the AC cuts out and the system just blows "vent" air. No cooling going on. Has anybody heard of this before?

Before you guys yell at me - I did a search in the FAQ and could find nothing. I also did a regular search but it also was rather fruitless. Could someone please help. My repair shop is at a loss. I have paid over $2,200.00 to get the AC fixed properly and would like it to operate like it should.

Thanks in advance for any help you may be able to provide!

 

[nsxtasy]

I don't know the entire answer but I'll tell you some things that might help narrow it down.

If I put the AC on auto (the left button on the climate control) the system seems to work OK. It is very cold when set to 60 but if I put it up to 61 degrees it doesn't seem near as cold. Is this right?

When you set the A/C on auto and you set the temperature to 60 or 61 degrees, it automatically puts the system in recirculate mode, so it recirculates the colder air in the car. It will seem much colder. If you set it to 62 or higher, it uses fresh air for the A/C. You can override either setting by using the recirculate button (the left button with the circular arrow) or the fresh air button (the second button with the straight arrow).

If I press the MODE buttons (to direct the air onto my face or feet) the AC cuts out and the system just blows "vent" air. No cooling going on. Has anybody heard of this before?

No, but there are two different buttons. As you correctly state, the MODE button should only change where the air gets directed (face, feet, combo, windshield, etc). However, there is another button, labeled A/C, that sets whether the A/C is on or off, to override the AUTO settings; when you press that button, you should see A/C ON or A/C OFF lit on the display panel. Is it possible that either (a) you are referring to the wrong button, and it's working properly, or (b) somehow the wires got crossed in connecting the unit, so that the buttons got switched?

How much experience does your mechanic have in working on the A/C system on NSXs? If he is at a dealer, he should be able to call Techline at Acura HQ for help with getting the problem fixed.

 

[Michigan NSX]

Re: Re: Help with AC please

Thanks for the reply Ken.

I don't know the entire answer but I'll tell you some things that might help narrow it down.


When you set the A/C on auto and you set the temperature to 60 or 61 degrees, it automatically puts the system in recirculate mode, so it recirculates the colder air in the car. It will seem much colder. If you set it to 62 or higher, it uses fresh air for the A/C. You can override either setting by using the recirculate button (the left button with the circular arrow) or the fresh air button (the second button with the straight arrow).

If I put the recirculate button on or use the fresh air button (the orange and green ones) the temp stays about the same, cool for anything down to 61 - COLD for 60.

No, but there are two different buttons. As you correctly state, the MODE button should only change where the air gets directed (face, feet, combo, windshield, etc). However, there is another button, labeled A/C, that sets whether the A/C is on or off, to override the AUTO settings; when you press that button, you should see A/C ON or A/C OFF lit on the display panel.

When I use the mode button (to direct the air onto my face for example) the COLD air stops and is replaced by cool air. It makes no differrence if the buttons make the display say AC On or Off. I get the same results.

How much experience does your mechanic have in working on the A/C system on NSXs? If he is at a dealer, he should be able to call Techline at Acura HQ for help with getting the problem fixed.

He is an NSX certified technician who used to be at a dealer and now owns his own shop (and has for several years). Because he is now out of the "dealer loop" he doesn't have access to "dealer only" info. I'm not wild about my dealer. And I especially do not want to go into the dealer and tell them I just paid $2,300.00 to get this AC fixed and it is still not right.

Thanks for all your input - any further ideas will be welcomed.

 

[prova4re]

I had allmost the same problem The dealer replaced the asperator fan and added 1 pound of the new freon. Now it blows ice cubes. We will see how long that will last.

 

[gheba_nsx]

I needed more freon and I resolved all AC problems (similar to yours)...

 

[Soichiro]

I doubt more refrigerant is the answer because the system was just converted and freshly filled. I think the aspirator fan is a good idea for checking - if it's not working the system may be confused and only be blowing truly cold air on it's lowest setting. First thing to do is get some temp readings from the vents and/or find a more qualified shop.

 

[jlindy]

What would the cost of replacing this fan be, parts and labor?

 

[nsxtasy]

Is that the same aspirator fan that's behind the vent just in front of the shift knob, and sometimes makes noise? If so, around $500 including parts and labor, I think.

 

[Michigan NSX]

OK - further details:

When I put it in one of the modes (face, face and feet, etc...) the AC turns off - EXCEPT if I put the fan on it's highest speed, or turn the fan all the way down to the "auto" position. As soon as I deviate from this (even by as much as turning the fan down one "click" from the highest speed) the AC shuts off and just cool vent air comes through. The "AC On" light remains lit.

Any insight on this weird gremlin?

 

[nsxtasy]

the AC turns off - EXCEPT if I put the fan on it's highest speed

Sounds like TSB 92-007.

 

[Michigan NSX]

Sounds like TSB 92-007.

No Ken - That isn't it. The blower motor works just fine. If I turn the motor one click off of "high" it slows down the one speed as it should and blows just fine. The problem is, when I do this, the "cold" AC air stops coming out of the vents and the "cool" vent air replaces it.

Thanks for all your help anyways.

 

[4Chin500]

Does the compressor cut out when you move the fan switch from the maximum position? I can't say for certain on the NSX, but most cars I've owned engage the compressor clutch constantly while the fan switch is in the high or maximum position. When the fan switch is moved to a lower position, the system cycles the compressor based on the cabin temperature. When the compressor cuts out you would notice a decrease in the temperature from cold to cool, as the freon not being circulated through the system. You could have a faulty fan switch, a bad temperature sensor, or the wiring to these components may have a problem. Just some other things to look at.

 

[jrehner]

Cool vent air?

When you say "vent air" I am thinking outside air which would not be "cool" at all in Arizona. I am following this as I don't think my AC is as cold as it should be but I have never used the Auto Climate Controll. I just hit the button for AC to turn it on and hit the Recirculation button for maximum cooling and make sure I have the fan on max (right control knob) all the way clockwise.

Does the climate control with its cooling adjustment etc work better somehow? Then you have to have the rt control knob all the way counterclockwise to "auto" and adjust the left knob for cooling, still turn the AC to ON etc....

 

[jrehner]

Ok--I reviewed everything and ask this--Michigan nxs has been using the climate control. Right knob to "Auto". AC set to "ON" and is using the left knob to control temp and if he turns it just off the coldest setting then and only then does a change in mode to face etc causes cooling to reduce drastically but the blowers keep going. Apparently at the coldest setting, the system recirculates automatically and you go off that and it brings in outside air (bad in AZ) to go with the cooling.

What happens when he does it like me? Ignores climate control and uses the mode settings? I would never want outside air to come in--Do you have the same problem when not using the climate control?

 

[nsxtasy]

Re: Cool vent air?

Does the climate control with its cooling adjustment etc work better somehow?

I don't think so. I believe the "FULL AUTO" setting merely means that the climate control will decide, based on comparing the temperature setting on the panel with the temperature sensor at the top of the dashboard, how to automatically set the fan speed, whether the A/C is on or off, and (depending on temperature being below 62 or not) the recirculate setting. I don't think the automatic functions give any greater performance than setting those controls manually. At least, that's based on my experience; if anyone knows more than that, feel free to let us know...

 

[jrehner]

So Michigan NSX--have u tried the AC on manual like I do instead of using the Auto Climate Control? Do u have the same problem or does not work correctly on manual?

 

[Michigan NSX]

I have tried going to the AC ON mode from the Auto mode, but not from the "everything off" mode. I will try that tomorrow and let you guys know what is going on.

 

[jrehner]

Everything off mode?????

You just put the AC "on" and make sure u do not use auto--so u do not have the rt control knob on auto and u do not hit the auto button on the left knob. Just use recirculate button until everything is cooled down and then try and use one of the mode positions--straight forward etc and see if cooling is still effective.

In AZ, I can keep recirculate on the entire time because my trips are short and it's just getting cool about when I get to where I am going...

 

[jrehner]

So what happened when u tried it strictly on manual?

 

[Michigan NSX]

The same thing as happened going from the Auto mode.

I turned the system OFF. Then went to AC on, put it on "Face" and cool vent air came out. Put the fan on Hi and I got cold AC. Ramped the fan back one setting - cool vent air again. I think I am going to have to take it back in.

 

[jrehner]

Hey Michigan NSX and everybody who has responded. Look at the Technical forum---there is person that has possibly the same exact problem that is looking for help--AC works on max but they turn down from there and boom--regular air-He does not mention what mode he has the AC in when he's doing this.....

 

[Michigan NSX]

Thanks - I will go look right now!

 

[SilverOne]

The same thing as happened going from the Auto mode.

I turned the system OFF. Then went to AC on, put it on "Face" and cool vent air came out. Put the fan on Hi and I got cold AC. Ramped the fan back one setting - cool vent air again. I think I am going to have to take it back in.

thanks for directing me here, jre.

My problem sounds very similar to the above description, the cold air will come in when I turn the fan to max with the right knob, and temp setting to 60. If I turn the fan down 1 setting, or change the temp setting a bit higher, then it blows only cool, and after sometime, the air actually feels warm. As for mode, I usally leave it in the fresh air mode, and not the recirculate mode.

Mine is a 91, and I dont' believe it's had any AC services. Would adding freon help? is that the solution? Or is there something more serious?

 

[jrehner]

Well I can only tell both you Michigan NSX and Silverone that I have found my problem---the fan behind the condenser on the driver's side is not working---maybe in both your cases, the AC is only cold on MAX and then is warm because of the same issue--you could have one or both of your fans not working--somewhere in the FAQ or elsewhere it was indicated to go to the front of the car and at bumper at far left & right to listen for the fans. If they are working you will definitely hear them and a small flimsy piece of paper or tissue would be sucked toward the condenser....

I haven't checked the fuses yet--there is one for each side and one for the overall climate control. Apparently it is common for one or more fuses to blow-change out and voila--works again...

 

[jrehner]

I checked FAQ (Trouble Shooting) Climate Control. Fuses 36 & 37 in fuse box under the hood control the condenser fans..You may not feel any difference in cooling from left or right if only one of the fans is off....Air would be cooler while moving....