Nissan X-trail 2002 - Air conditioner fan occationally won't run

[Kabelsalat]

Hi forum. Hope this question is within the scope of discussions.

Anyway - Today, there was very high humidity together with decreasing temperature (laying around or just below freezing point), and at a point, the air conditioner fan just did not start up when I started my car. After about ten minutes of driving, the fan started to run again.
Whitin the time period when the fan didn't operated, I tried many combinations and all possible fan speed settings from the air condition controller - neither did change anything, I did not managed to get the fan to start spinning again.

This led me to think there is some bad connection somewhere, probably sensible to combination of high humidity and dropping temperatures.
So I assume this may happen at later times too, and I want to prepare and have a multimeter laying around so that I may troubleshoot when it happens again.

Problem is that I cannot find any decent wiring diagram online. Those I find are either for other car models (I have this one button that toggles the fan speed setting, while the wiring diagram is for the model that have a rotational knob for fan speed - that is usual on the older model of X-trail)

That makes me having two questions:
- Does anyone have the actual wiring diagram for this car model ?
- Anyone have had similar problems and maybe have some knowledge on where i should look for weak contact points ?

Thanks in advance

 

[Bluejets]

Assume you mean the fan coil fan (interior unit).
There will be a protection thermostat of some description on the unit to avoid freezing the coils.
Question would have to be why do you want the air con to run if temperatures are at or near freezing.

 

[Kabelsalat]

Question would have to be why do you want the air con to run if temperatures are at or near freezing.

That's about the only practical way to get the fog away from the window.

However - disabling A/C did not make any difference, i.e. tha fan didn't start when A/C was turned off. Using my car for about six years, this is the first time this happens.

What coil freezing protection are you reffering to? I use temperature settings set to 19 deg. celsius or higher at winter time.

 

[shrtrnd]

I don't know if I have enough information, but I'm thinking like Bluejets, the AC system is doing what it's supposed to do.
Don't you have a heater option to use for defrost? Or can't you run the fan without engaging the AC?
It might help if you tell us the make and model of the car, and if you just don't have a heater coil in it.

 

[Tha fios agaibh]

@Bluejets: The compressor runs anytime defrost is selected to help remove humidity.

Could be fan relay or a resistor module used to control fan speeds. I had a resistor module go out about 5 years ago in my truck.

I would look at labeling on fuse panel to locate fan relay and take readings with the fan working (off, and at different speeds) so when it stops working you know where to look.
If it stops working, I'd use a test light as opposed to a voltmeter which can give you misleading readings.
Hopefully you just have bad contacts on an inexpensive relay rather than an expensive speed module which are used in newer models to slowly ramp up speed.

...Although we may be able to fix even that if its components are accessible.

 

[Kabelsalat]

I don't know if I have enough information, but I'm thinking like Bluejets, the AC system is doing what it's supposed to do.

Don't have that, btw - what is bluejet? WHen googling for that, I find it to be a sky phenomen or an airline company.

Don't you have a heater option to use for defrost? Or can't you run the fan without engaging the AC?

When the fan operate, it does operate with or without A/C. When not operating, it won't run regardless if A/C is engaged or not.
When I drive to work and home today, the fan was working without any problems.

It might help if you tell us the make and model of the car, and if you just don't have a heater coil in it.

Says in the title. It is a 2002 model of X-trail - petrol engine, also referred to as T30. Models after 2007 I beleive are refered to as T31.

 

[bertus]

Hello,

@Kabelsalat , I think that @shrtrnd is referring to post #2 made by @Bluejets

Bertus

 

[Tha fios agaibh]

https://cardiagn.com/2007-2013-nissan-x-trail-model-t31-series-service-repair-manual/

 

[Tha fios agaibh]

Perhaps bad connection at M99 see page 90 of power supply

 

[Kabelsalat]

Hello,
@Kabelsalat , I think that @shrtrnd is referring to post #2 made by @Bluejets

Bertus

Ah - thanks, I'm obviously blind and tired

 

[Bluejets]

@Bluejets: The compressor runs anytime defrost is selected to help remove humidity.

I'm well aware of how the systems operate.

 

[Kabelsalat]

Have had my car under roof and tried to examine any possible bad connection points - that's pretty much what I can do when the failure isn't present. Nothing found, all connection points seems good. No bad sounds from the fan motor itself. No visible or auditible signs of anything out of order.
Also - every wire is embedded in sticky tape and I'm not particular into unwrapping all that sticking mess, unless I have a strong indication of failure in a wire itself - not likely.

 

[Kabelsalat]

Update.

During Xmas holiday I've had 4-5 incidents where the blower motor wouldn't start. I've bought a cheap indicator light so that I plan to connect in parallel to the blower motor terminal, so that I'll have a chance to actually see it's providing voltage or not.

Anyway I'd managed to find an actually repair manual:
https://www.workshopservicemanual.com/m0072131-nissan-x-trail-t30-2000-2007.html

Most important information - summary:

• Electrical schematic on page ATC-37
• Trouble diagnosis on page ATC-83
• There is a device namely "Fan control amp" to adjust fan speed. From this I can't tell if 'full speed' - if the current is bypassed the "Fan control amp" or not.

Therefore I cannot draw a conclusion to whether it most probably is the blower motor, "Fan control amp" or the "A/C auto amp" that is failing.

 

[Kabelsalat]

Final update.

Have had the car to a repair shop due to another engine related problem, so I asked the mechanics to look at the fan blower as well (since I haven't get to make any measurements myself yet).

Turned out to be a loose connector on the inaccessible side of the A/C controller unit, and so it should be fixed now.

 

[Kabelsalat]

#solved

I can't find a button to set the thread solved - nor can't I find an "Edit" options for my own replies.