A/C Reprogramming?

[JPS48]

I've seen the goofy way Nissan has designed the ventilation system referred to previously in this forum but haven't seen anything specific as to whether it can be modified.

Currently, selecting either the 'floor/defrost' setting or the 'defrost' only setting engages the A/C without illuminating the A/C switch. You only discover it's on if you then switch to another setting at which point the light illuminates.

I happen to prefer the 'floor/defrost' setting most of the time but don't want the A/C running nor the mileage hit.

Does anyone know if there's a way to disable this from happening so that the only way the A/C is on is if I choose to turn it on?

And yes, I know all about the need to run the A/C occasionally and have done that religiously on any previous vehicle without the manufacturer assuming we can't think for ourselves.

[Promise Land]

A simple way to control the A/C compressor is to add a switch between you and the A/C compressor. You could add a simple toggle switch to the power wire of the A/C compressor which will allow you to stop power from kicking the compressor on/off.

[JPS48]

Hadn't thought of the secondary switch approach. I'd really like to be able to modify the original gear, something I hope can be done.

Wouldn't it be nice if it were as simple as changing the auto door lock function.

If there isn't an easy way, then I may pursue your suggestion, thanks.

[Codelicious]

Hadn't thought of the secondary switch approach. I'd really like to be able to modify the original gear, something I hope can be done.

Wouldn't it be nice if it were as simple as changing the auto door lock function.

If there isn't an easy way, then I may pursue your suggestion, thanks.

Canaan's suggestion would most likely be the easiest route to get what you want done..

Why do you want it to be off though?

[JPS48]

Cody,While Canaan's suggestion is a good one, at this point we still don't know that it's the easiest, if in fact a simpler solution exists, like a simple program change, a fuse removal, or something else.

There may not be an alternative but until I've exhausted any or all alternatives, I'd like to avoid what is essentially an 'aftermarket' or add on solution.

As for why I'd like it to be off, I've already cited the major reason: GAS MILEAGE! This is something that is already especially poor with the Versa, especially when compared to another car in our family that is 15 years old with similar size and displacement and regularly gets 30% + better mileage.

But let me list just a few of the other reasons:

1) I don't need it to run all the time

2) It makes the heater output, which already isn't very strong, even weaker.

3) I'd like the choice to be mine, not Nissan's 4) To me it's completely illogical, an opinion shared with just about everyone I spoken to about it.

5) Unnecessary energy consumption.

6) The fact the Nissan chooses to hide this from its owners by not having the A/C light illuminate is outright subversive. At least I give them credit for detailing it in the user manual, but not offering any options is unacceptable.

There are numerous posts on this site as well as others on this topic relating to other Nissan vehicles, I hope there are similar solutions for the Versa.

[Codelicious]

I understand why you want it off now, was just curious about it.

I'm not sure about any other solutions, I hope that your able to find what you are looking for. If I come across any information I will definitely let you know.

[Promise Land]

Well, you basically want to control the A/C compressor power wire's function to turn it off and on. A switch is something you could manually turn off and on from sitting in the driver's seat and mount where you wanted it to. You could probably remove one of the fuses for the A/C system. I don't know if the best fuse will be under the dash or in the engine room. If you figure out the best way to do it with a fuse, let us know. I'm sure other members would be interested.

[loudmax20]

Every car that's equipped with A/C does this.My mothers' Yaris does this, my sisters Chevy Aveo does this, my Nissan Versa does this, my 1991 Chevy Astro Van does this, my friends 1990 Ford Tempo does this, my dad's 1987 Toyota 4Runner does this.Yet the Nissan people are the only one's I have ever heard of complaining about it. I like it because my switch lights up and allows me to turn in off, maybe they only did that on the 07/08's but when its on and the car is warmed up it I haven't noticed the heat output to be any cooler than it is when the a/c is off, plus when the a/c is on with Defrost it de-fogs the windscreen so much better than with it off.

[Shad0wXCalibur]

Every car that's equipped with A/C does this.My mothers' Yaris does this, my sisters Chevy Aveo does this, my Nissan Versa does this, my 1991 Chevy Astro Van does this, my friends 1990 Ford Tempo does this, my dad's 1987 Toyota 4Runner does this.Yet the Nissan people are the only one's I have ever heard of complaining about it. I like it because my switch lights up and allows me to turn in off, maybe they only did that on the 07/08's but when its on and the car is warmed up it I haven't noticed the heat output to be any cooler than it is when the a/c is off, plus when the a/c is on with Defrost it de-fogs the windscreen so much better than with it off.

I'm gonna have to agree and say that what the Versa does with the compressor is absolutely no surprise. The earlier models (like mine) actually made it easier where you were able to hit the A/C switch in defrost and the compressor actually would stay off. Most cars don't even do that. It's normally on in defrost no matter what and the a/c button may usually not even be lit to show you. Car manufacturers aren't trying to build some conspiracy to suck gas or whatever. As a matter of fact, I average 30 mpg with the A/C on ALL the time to always keep the cabin comfortable and dehumidified. They do this because it defrosts your windows faster and keeps them from fogging up and so the compressor stays lubricated. You may have problems with it being locked up if you were to go through an entire winter with the compressor NEVER turning on then tried to use it on some hot day.

Not trying to bust anyone's balls. There may be valid reasons why someone would not want it to come on but there are also valid reasons why it does and to criticize Nissan for it is stupid since just about every car does this. It's definitely not a Nissan thing.

[JPS48]

To the last two respondents, be assured, not every manufacturer does this, but if a manufacturer chooses to force the A/C to engage on either of the two defrost settings, then they should at least let the driver know it is on by illuminating the A/C switch light as well as providing a way of shutting it off without having to change the air flow settings.

Fortunately my Versa doesn't get a lot of use, but that which it does has returned over 10% poorer miles per gallon when the a/c is on. At the current equivalent of $6.14/gallon (Imperial) or $5.11/gallon (U.S.), you can quickly appreciate how a 10% plus improvement makes a big difference.

At long last, I plan on pursuing a defeat switch for the A/C and am thinking the easiest way would be to tap into the wiring that feeds the underdash fuse panel which contains an A/C fuse. Said switch could simply reside in the dummy panel just above it beside the dash light dimmer wheel.

Does anyone see any issues with cutting the power at this location?

[JPS48]

Mission Accomplished!

Removing the 10amp fuse from the under dash fuse panel achieved exactly the results I was after so that was the wiring I tapped into.

I'm detailing here the steps I took for anyone wanting to do the same. I used the blank switch panel to the right of the dash dimmer wheel and electric mirror controls, all of which reside to the left of the steering column just above the fuse panel access door.

The following dash components needed to be removed to fully access the blank switch panel as well as the back side of the fuse panel, in this order (names from the Nissan Service Manual, not mine):

1) Fuse Block Lid (this is simply the pull off cover for the interior fuse panel to the lower left of the steering column)

2) Instrument Side Mask (LH) (this is the access panel on the side of the dash only visible when the door is open. It's easiest removed just by reaching up through the fuse door opening and pushing it outward)

3) Instrument Lower Finisher (this is the panel containing the previously mentioned switches which ends at the center console stack. It's held in place by what I refer to as 'spring clips' (clips & pawls in Nissan speak) along with two screws under the fuse panel door and just above the gas filler door and hood release. Remove the two screws first, then give the lower right corner a good 'yank' and you'll immediately experience how the 'spring clips' release at each corner.

4) Instrument Side Finisher (this is the section between the 'Lower Finisher' and the left side dash air vent. It should probably come off before the lower piece but as I couldn't find an easy way to do that, I let the removal of the lower piece force the release of its lower spring clips. Then the uppers released easily.

You then need to remove the blank switch panel. You could do this while leaving the switch bank installed in the 'Instrument Lower Finisher' but I found it much easier and less risky to un-do the three screws holding the switch bank in the panel.

You'll also need to release the fuse block from its mounting arms. There are two which are self evident and only need a simple pry from a very slim screwdriver to slip it off the two mountings.

Once this is done, you now have access to all of the wiring on its reverse side and it's relatively easy to identify which wire to cut. The A/C fuse is on the lower left, one location to the right. It is flanked on each side by a 15amp fuse. The wire from it is red.

This wire isn't very long, I suggest cutting it approximately mid-way along its exposed length. I then used closed end crimp connectors to attach the wiring that runs to the switch.

The most difficult part was cutting a hole in the blank switch panel to accommodate the switch since this piece has vertical and horizontal fins molded inside it. The switch I used is from Pilot and requires a 1/2" x 3/4" opening. I popped the blank out its mounting so this work could be done on my workbench. After careful cutting and filing, the switch fit perfectly. It offers a third terminal to ground it which illuminates the rocker but I chose not to use that since it's on all the time, switch off or on, and is very bright, even in the daytime.

Then it was simply a matter of reinstalling everything which I did in the following order:

1) Fuse block back on to mounting bracket
2) Instrument Side Mask (LH)
3) Switch bank back into Instrument Lower Finisher
4) Instrument Lower Finisher
5) Instrument Side Finisher
6) Fuse Block Lid

That's it, probably about an hour total.

Here are a couple of photos (no flash) of the finished result. In each, the switch looks like it's lit but that's just the lighting. It really isn't that bright, especially when viewing it from the normal driving position. And if you might be asking 'why blue?', well after all, it is A/C!





Hope the pics are viewable, it's been a while since I've posted any!