There doesn't seem to be a forum that is applicable to the air conditioner so hopefully a few people see this in here.

I have a brand new 2003 Xterra SE and find the air conditioner to operate very strangly, and unlike any other car I've had and unlike the manual says.

After toying around and testing it appears the 2003 A/C has been changed to operate in a semi-automatic mode, with the compressor coming on through some strange voodoo combination of the temperature control and who knows what else.

In my vehicle at least, it appears the A/C button is little more than a sort of manual overide to force the compressor to come on, although it doesn't always work that way. In addition, there are times that the temperature control is on hot, and the compressor will run for a while then shut off.

According to the manual, the compressor should come on in the defrost modes, but I'm seeing it come on it ALL modes, at seemingly random intervals. One thing that is certain though is that turning the temperature nob all the way to cold turns on the compressor.

I've talked to two dealers about this and they claim it is the correct operation of the new system. I find it hard to believe that in the new models there is no way to simply get outside air unheated and uncooled.

Anyone have any insights/clarifications.

If your A/C button is OFF, and your RECIRC button is OFF, you should get outside air without the compressor kicking in... UNLESS you're in Defrost mode. In Defrost mode, the compressor will kick in because that's the most effective way to defrost your window (dry air).

The rest of the time if the A/C button is ON, the compressor WILL kick in and out as it has to cycle to keep the air at a given temperature. Most newer cars work this way. Think of it as a cruise control alternatively gassing and letting up to maintain a relatively constant speed.

If it's coming on in all modes, then it's broke, and your dealer is clueless.

PNUTMNM,

--- quote ---
The rest of the time if the A/C button is ON, the compressor WILL kick in and out as it has to cycle to keep the air at a given temperature. Most newer cars work this way. Think of it as a cruise control alternatively gassing and letting up to maintain a relatively constant speed.
--- end quote ---

This is how I understand it SHOULD work as well, however on my vehicle it is doing this independent of the A/C button. I've now had two different Nissan service departments tell me this is the correct operation on the 2003 and that it was changed from 2002. Personally I think they are wrong and my A/C button is stuck in the ON position even though the light still turns on and off.

Do you by any chance have a 2003 or have access to one to test this. On my vehicle simply turning on the fan, and turning the temp down to cold engages the compressor ALL THE TIME.

Thanks for the info..

This might account for things...

http://www.nissan-techinfo.com/nissan/TSB/Nissan/54301.asp

Brent

Its funny that you found that since I tried to yesterday and couldn't. The dealer gave me a copy of the Service Bulletin which he said he'd never seen before yesterday. I wish I had it electronically because its actually quite funny.

Essential it says, and I'm paraphrasing...

...
On 2003 and later models...
If the mode selector is set to defrost or foot/defrost AND the outside air temp is about 36F, then the compressor will run with the mode selector switch in any position
...

Really, I'm serious. It says in defrost mode, the compressor runs in all modes. I asked the dealer what that meant and he didn't understand it either. I asked him what the A/C button did and he said that as he read it, the A/C button didn't do anything on 2003 models.

I smell a serious issue or recall coming. That service bulletin makes no sense and is written like its trying to explain away a problem.

Sorry, I have an '01. I agree with you, that service bulletin sure is a horseshit way to explain things.

khs,
Send me an email address and I can send you the TSB.

Just a quick note. I have a 2002 and the compressor kicks on and off when the AC button is active. JFYI. And is it common to hear the compressor kick on and off in the cabin? This is my first truck and in my previous cars you couldn't hear it but in the X I can. Is that normal?

I can hear it when I'm idling, but not while I'm cruising down the road...

What I hear is a slight 'thump' noise when the compressor clutch engages. At least that is what I think I am hearing.

After sending my vehicle in for service for the second time in the first week, the word from the dealership is that on the 2003 Xterra the compressor does indeed run all the time. Simply turning the temperature control to cold result in cold air through the vents, without the A/C button being "ON". Any time the fan is turned on, the compressor runs.

I haven't yet had a chance to talk to anyone with half a brain but at this point all indications are that the A/C button has no function at all on 2003 Xterras. In addition the manual's description of heating/cooling/defrosting is completely contradictory to reality. I'm supposed to get some official explanation from Nissan Consumer Affairs in the next couple of days.

Needless to say I'm pretty disappointed with this whole situation and wish I had kept my 2001 Pathfinder.

Oh puh-leeze, this is enough to sour your on your Xterra and make you long for your old Pathfinder? Gimme a break...

Brent

Give YOU a break Brent? I'd feel the same way if it was me. Perhaps not so much that the compressor runs all the time (if that's the way it was designed to run), but not getting a straight answer from anyone and Nissan. That, coupled with a very contradictory owners manual, it screams of a "problem" that Nissan is trying to sweep under the rug.

If I'd have traded my '01 X for an '03 X and had the same problem, I'd pine for my old reliable as well.

I would be pretty upset if the A/C compressor was on all the time. Performance suffers and gas mileage suffers.

There is no reason it should be on all the time.

Agreed, it's a dumb change, but it's a bit extreme to make someone wish they hadn't bought the vehicle...

Brent

As mentioned above, its more the run-around I'm getting that is disappointing. Other than this A/C issue I really like the vehicle. I do miss the 250 HP of the Pathfinder though. It will take some time to get used to.

My local dealer is starting to open up and hint that he thinks the A/C shouldn't work this way as well. However he also says he's talked to Nissan and it IS working as designed for 2003. He also admitted this morning that several people have similar complaints. This is at a pretty small dealership so I'm guessing this is only going to get bigger.

The dealership I bought the vehicle from wants me to bring it in to them to take a look. Since its about an hour away from me I haven't yet. I've gotten the same run around on the phone from them as well. It appears dealers aren't in the know about this new "correct" operation.

From what I've experienced and been told by the dealership, the A/C compressor on 2003 models runs anytime the engine is running and the fan is on. I'm still waiting to hear from a Nissan engineer. I'll post another upate when I have more info.

The dash switch isn't even shown in the 2003 wiring diagram so I don't know what it does. The diagram leads me to believe that whenever the fan is on at any speed the ECU decides when to run the compressor.

I wouldn't like this either, especially with a manual transmission.

That would certainly reinforce my theory that the A/C button does nothing but show a pretty little light. Even the service manager sort of shrugged when I asked what the A/C button does.

If you have it electronically, is there any chance of getting a copy of that wiring diagram? On a related note, where did you get it yourself?

Thanks,
Kurt

It would make me think twice about buying one.

Having the compressor kick in, or disengage when you don't want it to isn't fun.

click me

I have no idea of where this came from.

Well the plot is thickening regarding the compressor operation.

Nissan Consumer Affairs finally got back to me and informed me that on the 2003 models, the compressor runs anytime the fan is on and this is by design.

The funny part is that thanks to the nissan's service manual website snafu, I have found a page in the manual regarding checking the magnet clutch engagement (which I interpret as the clutch to the compressor) when the A/C button is on or off.

After I gave the service manual page number to the Consumer Affairs rep his tone changed a little bit and said he'd have to get back in touch with engineers. At least he admitted that it was confusing. For anyone interested its on page MTC-44.

Everything in print seems to indicate the A/C button works as expected. Everyone I've talked to says that the compressor runs all the time. This is quite odd.

Kurt

This is not a unique situation. The 2001 manual still shows the 2000 fog light wiring and they are NOT the same.

I have a 2003 and I can't recall ever hearing the compressor engage when having the button off (other than defrost). What I can attest to is that there is a definate difference in having the button on rather that off. When on the cold setting with the a/c button OFF, it gets very hot inside the cabin. Turning it on definately forces COLD COLD air out from the vents.

WOW.. I'm floored now.

I have had two dealerships and Nissan Consumer affairs tell me that the compressor runs all the time when the fan is on. Apparently your vehicle isn't working correctly. I really wish mine wasn't either.

I actually just talked to my local dealership for the 4th time. They informed me all they could do was do what Nissan said, and Nissan said it was working properly.

On a related note... When you show a page out of the service manual to a service manager he gets a little snotty and sarcastic, at least in my experience..

I'm going to be taking the vehicle back to the original dealership later this week with a comment regarding lemon laws and see what happens.

Kurt