Climate Control Totally Packed In

[Auto Spirit]

Hi Guys,

The above problem surfaced last summer, but now is a major pain in this weather!

The background....

I had my car at 355 International in Dunsford for a few weeks last summer as the bonnet & wings needed repairing. When I picked it up I was chuffed to bits but it wasn't until I got home that I realised the climate control unit was not working at all - it was working perfectly before I dropped the car off.

Unfortunataly, being busy with work and generally not thinking too much about it I just left the issue.

Now, I have read some old threads about the A/C being as prone to age-related fatigue as the speakers, but I'm wondering if all it is is that something has been disturbed under the bonnet. This is not beyond the realms of possibility as the wings, bonnet and front bumper were removed for repair and painting. Another fault I noticed was that the door lock/unlock switch on the driver side control panel stopped working at the same time.

Does anyone want to hazard a guess as to whether its something minor eg loose connection or a more serious issue.

As I am a clueless about what's where - an idiot's guide to diagnosing the problem would be most welcome. Cheers :-)

[Silver Surfer]

Kaz....help this fellow Nsx'er!!

This thread may be helpful..

http://nsxcb.co.uk/testvb/showthread.php?t=5940

SS

[Kaz-kzukNA1]

Hi, Auto Spirit.
Sorry to hear your problem...

Hi, Silver Surfer. Thank you for refering me.

I'm quite sure you are feeling the same but it would have been better if the car was returned to the place where you had the service as soon as you found the problem. They know what they have done...

Without looking at your car (92 JDM Auto??) and with limited information, it is going to be difficult but I hope I can help you a little so let's start with the basic.

....I was chuffed to bits but it wasn't until I got home that I realised the climate control unit was not working at all - it was working perfectly before I dropped the car off. ...........
1. 'not working at all'
Do you mean it is completely 'dead' like you don't get any lights (text such as 'FULL AUTO', TEMP', 'numeric figure' for the targetted temperature setup, etc) or LEDs (green or umber) just above the 3 buttons for recirculation, circulation and defog mode?

Or, you get the lights, LEDs and air flow but not being able to control the temperature?

Or, you get the lights and LEDs but no air flow?

Or, you get the lights and LEDs but air flow only at a certain temperature setup?

Any detailed information will be appreciated.

2. Self Diagnosis test
If you are getting the lights and LEDs on your CCU, you can perform the self diagnosis test.
As Silver Surfer suggested, if you follow the link http://nsxcb.co.uk/testvb/showthread.php?t=5940 , in the post #2, you will find an attachment file CCU-Diag.pdf.
Please follow the instruction to check the input/output to the CCU and let me know the result.
It may sound complicated but basically, you just
a. Turn the Ignition switch to ON (do not start the engine, one poistion prior to triggering the starter. Lots of lights on your meter display).
b. Turn the 'Fan Speed Dial' all the way unti-clockwise to 'AUTO'.
c. Set the temperature to 18degC.
d. Wait for a while (about 1min they say...).
e. Press both the 'AUTO' (big round shape button at the left of the CCU) and 'OFF' (big round shape button at the right of the CCU) button simulataneously.
f. Check to see if you get anything at the indicator 'A' through 'I' described in the pdf file.
g. Slowly turn the temperature setting to 32degC.
h. Wait for a while (again, 1min).
i. Once again, press 'AUTO' and 'OFF' button simultaneously.
j. Check for the indicator 'A' to 'I' again.
k. Remove the key to switch off the car.

3. Driver door lock/unlock switch

..... Another fault I noticed was that the door lock/unlock switch on the driver side control panel stopped working at the same time......
It may sound strange to you but can you still operate (up/down/left/right) the 'power door mirror'?
I presume your car is JDM.
If you insert your car key to the key hole of the driver door and unlock/lock it, does the passenger side follow the same status (unlock/lock) as the driver side?
The unlock/lock switch is very simple circuit. Basically, it just shorts to the chassis GND at each position. The switch status is monitored by the Auto Door Lock Control Unit (JDM) inside the cabin and it just reverse the direction of the voltage applied to the actuator to unlock/lock the door.

There are outside air temperature sensor, condensor fans, fuse, relays involved at the front section of the car so the answers to the above questions would be a good starting point.

Regards,
Kaz

[Auto Spirit]

Hi, Auto Spirit.
Sorry to hear your problem...

1. 'not working at all'
Do you mean it is completely 'dead' like you don't get any lights (text such as 'FULL AUTO', TEMP', 'numeric figure' for the targetted temperature setup, etc) or LEDs (green or umber) just above the 3 buttons for recirculation, circulation and defog mode?

Regards,
Kaz

Yep, completely dead - no lights, numbers, fans, nothing - so there's no power coming into the a/c control unit at all.

I'll take a look under the bonnet for loose connections as a start point.

Many thanks for your quick help Kaz and Silver Surfer.

Regards
Parvin.

[Sudesh]

Might be worth taking a look at the fuses. According to the hand manual, the heater controls and rear window dimister are on the same fuse, Check if your dimister works or if it lights up when you press the button. The fuse box for the the above is located on the inside of the car, on the passanger side foot well.

Power door lock fuse is under the bonnet

[Auto Spirit]

Might be worth taking a look at the fuses. According to the hand manual, the heater controls and rear window dimister are on the same fuse, Check if your dimister works or if it lights up when you press the button. The fuse box for the the above is located on the inside of the car, on the passanger side foot well.

Power door lock fuse is under the bonnet

Nice tip Sudesh, I'll take her out of the garage this weekend to have a look.

Cheers
Parvin

[Kaz-kzukNA1]

Hi, Auto Spirit.

Seems like you lost the power to the CCU after someone worked on the front section of your car.

Unless they decided to disconnect the connectors and forgot to put them back properly at the back of the CCU, you can loose power by the following reason.

1. Fuse
When you have a chance, could you try to operate the power door mirror as in my previous post above? There are several fuses involved and one of them for CCU is shared with other circuits including the power door mirror.
Could you also try the other question regarding the car key into the driver key hole?

2. Damaged wire
Not sure how the body repair work was carried out but any possibilities of trapped cable? Can be tested with the multimeter...

3. Damaged power circuit on the CCU board
Seems like your car is 92 JDM so unless the capacitors were replaced in the past, it is very likely to have lots of leakage and causing damage to the circuit board. However, from your post, I'll be surprised if this was the reason for your loss of power at CCU especially if it was working fine prior to the body repair work. Still, it can be damaged by poor handling of electronics side during any repair work....

Regards,
Kaz

[Auto Spirit]

Ok Kaz, I've noted the above and will check over those points.

Won't be til the weekend, but I'll update you on the findings.

Once again, thanks for your guidance.

Parvin.