A/C and Rear Defrost button problems

[mrballcb]

We bought a 2007 Versa S used with 78K about a year ago. The A/C and rear defrost worked normally. I removed the center console cover piece, installed an Alpine radio, and re-installed the dash cover piece. The ground for the alpine is screwed directly to the steel frame of the dash that connects to the floor, it does not use the ground wire in the stock harness (Alpine recommends this due to higher current draw). I did not remove the portion of the console having to do with the air conditioner.

I didn't notice it at first, but after a while my wife said that she couldn't turn off the A/C. I started experimenting. If I turn on defrost, the A/C and indicator light immediately come on. If I set it to vent or floor, the A/C and light stay on. I press the A/C button and it doesn't do anything. However, I figured out that if I hold it for about 15-20 seconds, it will turn off eventually. The colder it is, the longer I have to hold it. (The indicator light coming on when in defrost mode seems to be an opposite symptom compared to the complaint of many Versa owners that their A/C light DOESN'T come on.) Similarly, to turn the A/C on, I have to press and hold the A/C button too. Honestly, it's just easier to turn it to Defrost and turn it back to vent :-/

The rear window defroster does not work at all. No amount of pressing makes it come on.

The capacitive effect of the A/C button makes me think that I have either a bad ground on the circuit board and it's charging up or down very slowly, or I've somehow disconnected some portion of the wiring harness coming from the A/C controller. The lack of function of the defrost button makes me feel even more that it's likely a loose wiring harness.

This weekend I plan to pull off the center console cover and take a look at the wiring harness and look at the traces and solder joints on the board, if I can get it out easy enough (per the instructions at i-think-i-rear-window-defoster-is-broke ... l#p5862108).

It kinda looks like this layout:
http://www.courtesyparts.com/versa-hatc ... _6432.html
Leads to this part:
http://www.courtesyparts.com/27520m-bas ... 32105.html

Any other suggestions? I don't want to replace a part if it's simple to fix. I don't expect it to be trivial because it takes a bit of work to get down into the console, but I don't think the problem or broken part will be difficult to fix. I don't particularly want to spend $160 for this, so any suggestions or insight are appreciated.

...Todd

[JoshH]

Any updates on this? My defrost button is giving me problems when the temperatures drop. I guess I need to open it up and check it out.

[mrballcb]

I haven't had a chance to work on it yet. Weekends have been busier than expected. This coming weekend is busy on Saturday, but Sunday can potentially be a time when I can dig into it.

[aranciata-oz]

Hi guys ... any updates on what eventually happened? My wife's Versa (stupidly named Tiida here in Australia) has had the same problem ....

Both the defogger and AC buttons ended up being very intermittent in operation of late ... naturally I opened everything up, and sprayed some electrical spray cleaner into the tiny tactile buttons ... well in normal circumstances that would fix things by clearing the dirt (like it did to my previous digital camera), but now both buttons are completely DEAD! I can't turn on the defogger/demister and AC anymore!

I had a good look at the two tactile buttons to see if I could remove it and replace them with buttons from the local electronic store, but alas, no luck, because they look a little too 'embedded' into the circuit board ... it may be a case I need an auto electrician to replace the whole AC control unit, but he would need to source the part from Nissan.

Anyway, just wanted to know what was the end result of your incidents above ...

[tonyaxxess]

Hi, i just finished fixing this issue in the sister in law's 2008 nissan versa. Her A/C button was working ok, but rear defrost would not come on, and living in Calgary, AB, you NEED this in the winter. Was able to source out a complete heater control unit from local wreckers($125) from a Versa with low km's. Had to take off top vent panel, stereo, just to get at it. Do not unplug Air bag light, as you'll have issues, simply remove entire piece. You'll need some needle nose pliers to release cables from old unit. Be sure to take some quick pics/notes to know which cables go where when re-assembling. Will post some pics when i figure out how. Any questions, please ask!