A31 Digital Climate Control

[daisu]

Well guys, after about 6months of not doing this, I finally got off my arse and did it, and it works!!

Here is the link to the original thread where we discussed options and there are a few more links in there to some usefull sources.

Thanks to a few people for helping with wiring diagrams and what not.

First thing I did was purchase a digital unit and sub loom, then if you are familiar with the conversion in S13 all you have to do is unplug the analogue subloom and replace it with the digital subloom. But since digital control was not an option in the A31/C33 there is no subloom to unplug, it's hardwired into the body loom. So I did a bit of experimenting.

I bought an analogue control unit and subloom from an S13 and plugged the S13 analogue unit into the ceffy and it worked straight away (easy replacement if your cefiro analogue unit stuffs up). So I came to the conclusion that the A31 wiring is identical to the S13 wiring when the analogue subloom is used.

So the next logical step was to repin the analogue loom using the S13 guide, but if you have ever removed your control unit, you will notice that there is next to no slack in the loom and there is no space to get your hands in there unless you remove the dashboard. Not keen.

So I made a new loom (I'll call it a hybrid loom because I can't think of anything else...shutup). It connects to the 3 plugs from the analogue loom and has 2 plugs on the end to connect to a digital unit.

There is only 1 problem now.. I couldn't find any plugs that would fit in the digital unit so I had to butcher a subloom to use the 2 black plugs, and I couldn't find any sockets that would suit the original plugs, so I soldered some PCB header pins onto a PCB experimenters board.

This is how it ended up looking

In the first picture you can see the 2 black plugs from the analogue loom plug onto those pins, and the white plug fits in that white socket.

In the 2nd picture you can see my awesome soldering skills and the two plugs that fit into the digital unit.

Functionally it is completely fine, and the board doesn't need to be that big I just haven't been bothered cutting it down, but it looks like dogs balls and the board wouldn't need to be there if I had a proper socket thing.

If you want to make your own conversion loom I can supply pinnout details.

Thanks, Luke

Edited April 10, 2008 by daisu

[toffy]

nice, i was thinking of doing this myself , sounds difficult the way you explain it though , i have spare all the wiring for cefiro heater controls though, wouldnt it be easier to just change the plug on the back of the digital heater control thingy?

[TonyL]

I'm confused...

so you ended up making your own digital sub loom? which is different to a s13 sub loom?

[daisu]

Basically, there is no sub loom in a cefiro. But the wiring in the cefiro is equivalent of having an S13 with analog subloom plugged in.

All it does is rearrange the wiring (exactly the same as repinning the plugs), but is alot easier to install compared to rearranging 32+wires.

[daisu]

Guys, I found a japanese site with wiring diagrams for the digital climate control loom. This loom plugs into the cefiro loom and adapts it to suit the digital unit.

Prototype #2, it's no where near as good looking as the jap one, but it'll do for the moment. Planning to redo it this weekend.

And it works!!

[Lum]

I take it your car came with the standard manual controls, and the analogue climate control you refer to is the one that looks basically the same only with the addition of an Auto button and the hot/cold slider is replaced with one marked 20/25/30, ie this one

If that's the case, am I right in saying it's simply a case of removing that analogue unit, chopping the plugs off and soldering on the plugs from the digital unit? I don't need to follow this guide that has me installing sun sensors and temperature sensors and so on?

Any chance you could draw up a wiring diagram?

Edited April 3, 2009 by Lum

[daisu]

Yes and no Lum,

there are 3 control units for the aircon in nissans.

Regular aircon (only option available in USDM 240sx, and some JDM S13) this is the one that has COLD-HOT written on it and no auto functions.

Analogue climate control (available in JDM S13, this is the only option available in laurels and cefiros) marked 20/25/30 and has auto fuctions like pictured above in your link.

Digital climate control, pretty self explanatory (different models available through silvia/skylines)

That guide (installing sun sensors etc) is for USDM 240sx models (and JDM models that didn't have climate control). You don't need to follow that as your cefiro already has the sunload and temp sensors.

The difference between the analogue and digital units is the wiring order. All of the wires are there, but they are arranged differently.

The analogue unit has 2 black plugs and a white plug, where the digital unit only has 2 black plugs.

You don't need to chop the plugs off as they are the same shape, they just need the wires to be rearranged, but that is pretty difficult to do in the cefiro.

So the easiest option is to make up a loom that rearranges the wires to suit the digital unit.

S13's have it easier, as that part of the loom that needs to be rearranged can be removed and replaced with one that suits the digital units.

http://www.a31cefiro.com/ryuuyou/air_con.htm

It's a japanese site, so you'll have to run it through a jap translator.

In the picture above, the large black connector on the left needs to be removed from a climate control unit (either that or you can press pins into the connectors on your cefiro loom)

The 2 black connectors on the right hand side can be sourced from an S13 climate control loom.

Or, if you want, I can source the parts and wire up the loom for you.

Edited April 3, 2009 by daisu

[Lum]

Or, if you want, I can source the parts and wire up the loom for you.

If that includes the climate control unit I may well be interested I have no idea where I'd get one here in the UK.

I see where I'm getting confused now though. The UK S13 (sold as a 200SX) came with the hot/cold slider the same as the US 240SX and since A31 info is very thin on the ground I've been doing most of my research based on the S13 and R32 which are more common over here.

[daisu]

Yeah, even here it is hard to find good information for the cefiro. Alot of the S13 and R32 information translates over to the cefiro/laurel but it's all the little things that are slightly different where the information lacks.

Digital units are pretty easy to get around these parts, last time I checked they set you back about $100 or so.

[Lum]

Yeah, even here it is hard to find good information for the cefiro. Alot of the S13 and R32 information translates over to the cefiro/laurel but it's all the little things that are slightly different where the information lacks.

Digital units are pretty easy to get around these parts, last time I checked they set you back about $100 or so.

That's a little less than a tank of fuel for the Ceffy, at UK prices

As soon as I mentioned this, my GF asked if she could have one for her S13 (they are hard to get over here). She'll wire that up herself though if the subloom comes with it as it's well documented for the S13 and she's a lot better with a soldering iron than me.

I suspect you'll want some cash for the work too

[daisu]

Yeah, making the loom involves a few hours work sourcing and stripping the parts, but it's not really that difficult. I mentioned on another forum I'd knock them up for $100 + parts.

Does your girlfriend's S13 have the hot/cold or the 20-25-30 type?

[hansmaniac]

Yes and no Lum,

there are 3 control units for the aircon in nissans.

Regular aircon (only option available in USDM 240sx, and some JDM S13) this is the one that has COLD-HOT written on it and no auto functions.

Analogue climate control (available in JDM S13, this is the only option available in laurels and cefiros) marked 20/25/30 and has auto fuctions like pictured above in your link.

Digital climate control, pretty self explanatory (different models available through silvia/skylines)

That guide (installing sun sensors etc) is for USDM 240sx models (and JDM models that didn't have climate control). You don't need to follow that as your cefiro already has the sunload and temp sensors.

The difference between the analogue and digital units is the wiring order. All of the wires are there, but they are arranged differently.

The analogue unit has 2 black plugs and a white plug, where the digital unit only has 2 black plugs.

You don't need to chop the plugs off as they are the same shape, they just need the wires to be rearranged, but that is pretty difficult to do in the cefiro.

So the easiest option is to make up a loom that rearranges the wires to suit the digital unit.

S13's have it easier, as that part of the loom that needs to be rearranged can be removed and replaced with one that suits the digital units.

http://www.a31cefiro.com/ryuuyou/air_con.htm

It's a japanese site, so you'll have to run it through a jap translator.

In the picture above, the large black connector on the left needs to be removed from a climate control unit (either that or you can press pins into the connectors on your cefiro loom)

The 2 black connectors on the right hand side can be sourced from an S13 climate control loom.

Or, if you want, I can source the parts and wire up the loom for you.

Hi Daisu,

I have also tried making a harness for the s13 digital climate control and installed in my a31. Funny thing the Fan Blower dosent operate and same goes with the tempreture settings. The On/off button fan/auto/ac and the blower positioning button does operate correctly. Did you have any similar propblem as mine? Before my climate controller is the regular type that you mentioned that uses a driffent type of looms(two white connectors) but there is also the black connector loom in the dash which is 20pin and 16pin which i plug in with my new rewired loom and s13 digital climate controller. I tried using the analog controller before (which have auto func. and 20/25/30 temp mark) that i borrowed from a friend a31 and connect with the plug connector in my dash but it did not function at all. Do you have any ideas what might caused this problems? i suspected that my a/c system dosent have those sensors that the a31 with anolog controller have.

[daisu]

hansmaniac -

As far as I know, all A31 and C33 had analogue climate control, which means they will all have the required sensors.

If yours looks like the one in the top of this picture then you should have all the sensors.

I did not have any problems with the fan or temperature settings, they worked straight away.

If your fan blower and temperature settings don't work, you may have a faulty digital unit, or you may have incorrect wiring.

Plugging the digital unit into the A31 without using a rewired loom can result in permanent electrical damage to the digital control unit.

Double check your rewired loom against the wiring table here http://www.a31cefiro.com/ryuuyou/air_con.htm

Where are you located?

[Lum]

Yeah, making the loom involves a few hours work sourcing and stripping the parts, but it's not really that difficult. I mentioned on another forum I'd knock them up for $100 + parts.

Does your girlfriend's S13 have the hot/cold or the 20-25-30 type?

She has just the hot/cold slider so will need the sensors and related parts too. She is however perfectly capable of wiring up everything herself (she's just a lot less likely to get around to it if it's for my car than for her own ) this is what she says she needs:

The unit itself

harness

mode door/air-mix motor

ambient temperature sensor

sunload sensor

internal sensor

this weird tube thing that I think is called an aspirator, it's to separate the internal sensor so it gives accurate readings

blower motor controller/resistor pack

apparently there might also be a relay needed?

I believe I just need the unit itself and the modified loom, and installation is basically pull the surround off, unbolt the unit, plug in the new one with this adaptor loom and put it all back together again?

Oh and postage to the UK

[daisu]

Yeah that all sounds about right to me.

The relay for your girlfriends S13 should come as part of the harness.

[Lum]

Yeah that all sounds about right to me.

The relay for your girlfriends S13 should come as part of the harness.

Excellent, PM me the bill and your paypal address then, I guess.

[hansmaniac]

Daisu,

Its confirm, my climate controller is the regular type and its not the same as the one you posted above pic. It dosent have that auto functions. I even open up my blower speed sensor and its the the one with holes like USDM type.... Dammit

Looks like i need to find a complete set of sensors and harness to use a Digital controller. Anyway im from Malaysia.

[daisu]

Lum, I'll have a look for the parts over the weekend and give you a more accurate idea of the cost.

Hansmaniac, I didn't realise that the malaysian models were supplied without climate control. Putting in climate control will involve doing the same things as the USDM S13,

[hansmaniac]

In my place actually not all a31 climate controller are like mine. Some friends of mine also have the climate controller just like yours (with auto func and stuff). Maybe im just unlucky

[cefiro new user]

hello, i'm a cefiro new user, now i have a problem for my cefiro a31...the air cond controller is burm ...

can u tell me about this is fix for what car?? and how about the cefiro a31 wiring and this digital climate control loom wiring ??

can u tell me about the wiring diagram?? thank you

And it works!!