Aircon Diagnostics (R33)

[RANDY]

I did some diagnosing recently using some found guides, but I found some more options and details worth mentioning and I intend to update this thread with images of the various sensors and actuators.

Hold OFF for 5 seconds within 10 seconds of turning ignition to ON.

1) A/C unit should light up all characters and lights with the exception of the backlight. In any diagnostic mode, the error codes (if any) will alternate. (e.g: 25/26/25/26/25/26/25/26/ etc)

2) Press UP for sensor check (2) and wait.

20 - No faults

21 - Outside air sensor

22 - Inside air sensor

23 - Water temperature sensor

24 - Intake temperature sensor

25 - Sunload sensor (must be in sunlight to pass)

26 - Potential Ballast Resistor

27 - Refrigerant temperature sensor

3) Press UP for door-position check (3) and wait.

30 - No faults

31 - Face

32 - Face/Foot

34 - Foot

35 - Demist/Foot

36 - Demist

4) Press UP for manual actuator motion check (4) and wait. The fan motor show ramp up if it is working. Press the DEMISTER button to cycle through the following modes.

41 - Face

42 - Face/Foot - Recirculating

43 - Face/Foot - Fresh

44 - Foot

45 - Demist/Foot

46 - Demist

5) Press UP for temperature sensor check (5). Press the DEMISTER button to cycle through the following sensors.

- Outside temperature

- Inside temperature

Press the FAN button to adjust the sensor temperature + or - 3 degrees with the UP and DOWN buttons. The change is saved but the new temperature is not displayed in the diagnostics. This is good for fine-tuning, but settings will be lost if the unit is ever disconnected or the car battery is replaced.

To exit diagnostics, press AUTO.

Notes:

* If either of the temperature sensors are way off (e.g -25C), they might be disconnected or faulty. The inside sensor is

behind the grille in the dash where the antenna height button is. I have confirmed by spraying contact cleaner into it

while on diagnostics mode and it shot from 18C to 5C for a few minutes. I do not know where the outside sensor is.

* As mentioned above, if the sun-sensor is not in sunlight, it will throw off a "25" code which you can choose to ignore if

you are testing in the shade. It is a small round circle in the passenger-side demister vent about the size of a 10c coin.

It can be removed easily after the demister vents are popped out with a plastic prybar. Do the driver side first.

* If you are getting either hot or cold air no matter what you are selecting, it will most likely be the "26" actuator by

the drivers left foot. Its job is to mix between the heater core and regular air. It may move a little or not at all, but

for it to seal off from the regular air or heater core air, it needs to have a full range of motion. The unit can sometimes

be opened and fixed by bending one of the metal contacts back in place that tells the actuator when it has reached its

limits. I replaced mine with a new one. Three screws hold it to the aircon box, and the door-flap rod is connected with a

clip that requires a fair bit of force on a set of pliers to pop off.

* If you have a clicking sound on startup and MODE selections, it is a common fault with R33's probably due to age and

Australian heat and the proximity of the actuator to the surface of the dashboard. This actuator is known to eventually

break teeth off one of the internal gears as uses some teeth more frequently than others for daily operation. There are

guides on opening these units and rotating the gear 180 degrees so that it uses teeth that are previously unused and in

good condition. Opening the unit is very difficult and I was not able to do it.

That's the easy part, getting to the unit is almost impossible with a Series 2 with airbags unless you partially remove the

dashboard. There are guides for series 1 whereby you can reach it by hand after removing the glovebox (5 minute job) and

some claim to have swapped it successfully in an airbagged series 2 by shifting the fan motor and airbox, but I tried this

and could barely even touch the actuator, much less get a socket on the two bolts holding it in. I replaced it with a new

item after partially removing the dashboard. Getting to the point of removing the dashboard takes me about an hour, perhaps

less, and once at that point, I could lift the dashboard up 10 inches or so... enough to get two hands and a ratchet in

there to remove the actuator easily.

My "26" Air Mix actuator and a replacement part.

[RANDY]

27730M (up under the dashboard)

277??? (driver footwell) Potential Ballast Resistor opened up. Arcing occurs due to weakened/worn metal contacts and rough roads. Mine arced to the point it broke the track and ate halfway through the PCB.

[adam1982]

awesome post mate! stumbled across this when I was trying to find how to stop the dreaded a/c clicking noise - or more descriptive, a way to get to the actuator in a s2 with the airbag. For the life of me I couldn't even get my hands in there to touch the unit, let alone remove it. I've even got the missus to try (way smaller hands then mine) and whilst she can touch the unit and almost get to the first bold, no joy.... nothing to show for it, but lots of small cuts.

I like your idea of only partially removing the dash (I feared my only solution was a full dash removal) and i've just scanned through predators full dash removal guide. (Link here) and found some photos that were still working (Link Here)

I'm wondering just how far into the dash removal you had to go, to be able to lift it up 10cm or so?

or if since you wrote this post, you may have had another idea on how to get to the actuator? - i'm really not keen on removing the entire dash or doing 98% of the dash removal, with the remaining 2% being the difference between taking the dash out of the car or not?

Any ideas/info you could provide would be greatly appreciated! Anything to save me from either ripping out the entire dash, or slicing my hands to pieces

Cheers

Adam

[RANDY]

Hey mate! Thanks for the feedback!

I think I used those exact words somewhere in the DIY post!: http://www.skylinesaustralia.com/forums/topic/301992-diy-fix-cluncking-noise-in-dash-r33s/

"For the life of me" I couldn't get my hand in there either. I scratched up the back of my hand quite a bit and could just manage to get a fingertip on the side of one of the bolts. I pulled out the glovebox, the aircon vent on the passenger side, the stereo and facia, the vents... there is just no way of getting to it.

Luckily, I have pulled my dash out before when it needed new airbags, and I've had my cluster out a few times to fix the tacho and change globes... same with the stereo. Once those are out, it's just a couple of screws per panel and eventually the whole thing is ready to take out of the car. That's the stage I was at but the last time I pulled it out of the car it had no front windscreen in it. I don't know if you can take it all the way out with the screen still in, so I just got to that point and then lifted it up so I could two hands in there easily.

Honestly, to do it right (especially if you have bought a new actuator), you should just bite the bullet and pull the dash up. It is extremely easy. If you haven't done it before it looks daunting, but trust me... it's very very simple.

If you undo a nut and take a panel off, put the nut back on the thread afterwards. If you take three screws out and pull a panel off, pop the screws back in the holes of the panel and put masking tape across it so they don't fall out or disappear. I think I can pull a dash out in about an hour now, but the first time you just undo stuff and wiggle until you work out what's holding something in.

The bonnet popper got me the first time, but it's just two bolts and you slide it down.

The surround of the glovebox is held on with clips after the screws are removed and I broke one of mine as it came out. I glued and graphite powdered it back together and it's perfect again.

The a-pillar covers were a bit of a dick... you're supposed to remove the c-pillar (rear window) covers first, as the a-pillar covers slip underneath them. I unbolted the passenger grab-handle and slipped the a-pillar cover down and out of the back piece and then gradually popped the clips towards the front.

So, bad news is: no other way if you can't reach it.

Good news is: it's easy and I am 100% confident that anyone can do it in a weekend the first try if you have basic tools and persistence.

If you don't already have these, I highly recommend these tools for any interior work:

http://www.supercheapauto.com.au/online-store/products/SCA-Door-Trim-Remover-Set-5-Piece.aspx?pid=282096

You won't scratch any of your interior with these, and the thick pry-bar is excellent for popping clips that have never been unpopped (a-pillar in particular).