Aspirator fan or climate control unit fail ?

[asylum]

I changed my central console for a SoS one to put a double din aftermarket radio. I did not put the aspirator fan back beyond it (as there is nothing to attach it). Now the air is only blowing when I am on the max position with the right knob. No more intermediate blower speed whatever the mode. I think this has nothing to do with the absence of the aspirator fan and my climate control must be repaired. Or am I wrong ?

This is the whole assembly that I did not installed back :

If I am right, it is just used on the full auto mode (auto + right knob turned full left below the 0 position) ?

 

[Old Guy]

I don't think its your aspirator fan, although there might be a failure code because of a lack of the air temperature sensor.

The most common problem when the main fan fails to operate on anything other than the maximum speed setting is a failed blower motor power transistor module in the heater fan assembly. There is a climate control unit self test and function test (two separate items). If the self test and function test work out, the CCU is probably OK and it is the power transistor that is faulty. The CCU self test will probably show open sensor on the interior sensor because you have disconnected the aspirator fan.

 

[Jinks]

It is the cc unit. The unit still runs without the aspiration fan. The aspiration fan only comes into affect when both the temp and fan knob are switched to auto.

 

[asylum]

Thanks Jinks. It confirms what I thought.

 

[Kaz-kzukNA1]

For your reference, if you disconnect the aspirator fan (cabin temperature sensor), CCU board will use fail safe value of 25degC (77degF) as the fixed cabin temperature and use it for the water valve control (blower air temperature control).
Cabin temperature sensor is in use regardless of whether the fan speed control (the right dial) is in Auto or not but the entire water valve control is not that sophisticated and I must say bit vague and very slow to react for the cabin environment change.

All of the sensor input will be ignored if the target temperature (the left dial) was set at either MIN (18degC, 64degF but the display could be 60) or MAX (32degC, 90degF) and it will continuously cools down as well as warms up the cabin temperature regardless of the target figure (18/32degc, 64/90degF) as long as the evaporator temperature is above 3 – 4degC (37 – 39degF) to prevent it from freezing.

As others mentioned, if your CCU board stopped working when your aspirator fan was disconnected, it’s the board failure and not the sensor input related as the CCU board will use the fail safe mode.


Kaz

 

[Briank]

The ccu is always in AUTO, the only difference is full auto which is the fan speed is under control of the ccu. Once the aspirator fan sensor is disconnected and the ccu senses it being gone it just runs a preset program using the condenser temp. sensor and the outside air temp. sensor. Most likely you just had a coincidental failure of the ccu while you were messing with the console.

Oh and the power transistors very seldom fail so get the ccu fixed before deciding to replace it.

 

[asylum]

I just installed a repaired unit I got from SoS and the problem is solved. By the time, I reinstalled the aspiration fan somewhere behind the center console.

 

[ChrisMD123]

Hi asylum,

I think I'm having the same problem you mentioned, but I just wanted to check. Right now, my NSX's fan seems to have only two modes: asthmatic squirrel and typhoon. When I'm in FULL AUTO and on anything but max cool, I get the squirrel. If I spin the fan knob to anything except full, I get squirrel. But if I'm in FULL AUTO and go max cool, or if I go max fan on the right dial, I get the typhoon.

Is that the same thing that you were getting, that was fixed by replacing the climate control unit?

Thanks,
Chris