Climate into RHD avant

[S2central.net]

On Sheet 6, to close things out it is only J44 that we are concerned about. You should have the relay block on the donor loom - I dunno if this fits directly into S2 carrier - its no big deal really but the donor loom will look after connectivity to terminals 30, 85 & 86 on that relay - tracks 56, 57 on the B5 schematic.

All you need to do is wire up N25 by linking the gn/ge wire on donor loom T10p/1 to the S2 at T5g/3 (a green plug in the auxiliary carrier) - the wire should also be gn/ge on the S2.

And that's it for now...

[S2central.net]

Oh just one last thing... you could retain use of F73 logic by splicing it in series with sw/bl feed into J44... low system pressue (no gas) will prevent the compressor relay from being activated... CCU must have some other logic to do this but it's an option.

The switched side of F73 supplies power to manual system on S2 via a sw/gr wire which you can find at T8a/2 before it makes its way into Aux position 4 on pin 11 of that relay block. Personally I would use it cos its there... probably deleted on the climate cars to save a buck.

[johne]

Oh just one last thing... you could retain use of F73 logic by splicing it in series with sw/bl feed into J44... low system pressue (no gas) will prevent the compressor relay from being activated... CCU must have some other logic to do this but it's an option.

The switched side of F73 supplies power to manual system on S2 via a sw/gr wire which you can find at T8a/2 before it makes its way into Aux position 4 on pin 11 of that relay block. Personally I would use it cos its there... probably deleted on the climate cars to save a buck.

Paul, not sure I'm with you here but you must retain the logic of F73. F73 is probably the most critical component in the A/C system, manual or climate and certainly isn't deleted in the climate system. Power is fed to the compressor clutch N25 by relay J44 in your description and J44 is fed by F73. The signal feed to J44 comes from D8 on the climate CCU and the state of F73 is monitored by pin C3 on the CCU.

Together, this gives a logical AND system so that there has to be gas in the system AND the CCU wants to demand A/C compressor on AND the system hasn't been on so much that the pressure in the system has dropped too low so the evaporator freezes up. F73 is the logic element for the CCU.

John

[johne]

Sheet 5 is pretty much exclusive to donor climate loom with the exception of two pins for ECU signalling...

A2 is a sw/ge wire on T10/6 - a brown blug if you have it on the donor loom - connect this to T5h/2 on the S2 (or T10e/2) where it should land on pin 41 of the ECU and pin 3 of the afterrun relay to signal that aircon is turned on... This in turn is used by afterrun relay on the manual system to turn on the fan to speed #1... Looking at S2 climate loom it is curious that CCU pin D16 is also used for this function so you can wire that up to terminal K4 in the S2 fusebox if you wish. Bit of an odd one that... makes me want to buzz that out on the S2 to be sure

Whilst pins D16 & A2 have apparently the same function, i.e. they both go active to signify A/C on, I'm not convinced they have identical logic behind them and may not switch the same under all conditions. Moreover, if I were wanting to use the A/C on output to drive a fan relay I'd be using D16 as this is the one with the current drive behind it. Now as it happens, on the S2 it's the after-run relay that's used for the low speed fan when the A/C is on and this is an electronic relay so the current draw may well be very low and either D16 or A2 would do, but I'd still opt for D16 as it's the current drive one and where the fan relay is connected by Audi.

May also be that one output is active high and the other active low but I haven't checked that.

John

[S2central.net]

Paul, not sure I'm with you here but you must retain the logic of F73. F73 is probably the most critical component in the A/C system, manual or climate and certainly isn't deleted in the climate system. Power is fed to the compressor clutch N25 by relay J44 in your description and J44 is fed by F73. The signal feed to J44 comes from D8 on the climate CCU and the state of F73 is monitored by pin C3 on the CCU.

Together, this gives a logical AND system so that there has to be gas in the system AND the CCU wants to demand A/C compressor on AND the system hasn't been on so much that the pressure in the system has dropped too low so the evaporator freezes up. F73 is the logic element for the CCU.

John

John - agreed on importance of F73. It does exist on B3/B4 climate system... and also on the MY96 system on the B5 but it was deleted for MY97 - at least going by US Bentley diagrams. It does not appear on the UK diagram for MY98 either.

In short, I would retain F73 when converting to climate regardless of what year the head unit was sourced - pretty easy to do by using B75 schematics as a reference.

[S2central.net]

Whilst pins D16 & A2 have apparently the same function, i.e. they both go active to signify A/C on, I'm not convinced they have identical logic behind them and may not switch the same under all conditions. Moreover, if I were wanting to use the A/C on output to drive a fan relay I'd be using D16 as this is the one with the current drive behind it. Now as it happens, on the S2 it's the after-run relay that's used for the low speed fan when the A/C is on and this is an electronic relay so the current draw may well be very low and either D16 or A2 would do, but I'd still opt for D16 as it's the current drive one and where the fan relay is connected by Audi.

May also be that one output is active high and the other active low but I haven't checked that.

John

Agreed there mostly John... D16 is the proper way to engage speed 1 - it is generic to all engine types. D16 is an 'active low' output as far as I can tell - it is a switched path to 0V.

On the S2 installation however, the afterrun relay does the same job by way of CCU --> ECU signalling from CCU pin A2, so strictly speaking you don't really need D16 wired up to make it work.

That said - I agree that using D16 is superior as it gives a belt and braces approach such that a failure of afterrun relay may otherwise prevent the fan being activated when climate is turned on.

[S2central.net]

Just found a simpler way to hook up F118 from S2 manual system into the MY98 B5 system that avoids messing with wires under main fusebox...

F118 sits alongside F23 in the condensor housing... Working in that area do the following, whilst being careful NOT to cut any black/green wires -

1 - cut the sw/ge wire (black/yellow) that feeds into F118 - insulate the end coming from the loom and leave enough on the switch end to make a new splice.

2 - splice that sw/ge wire on F118 into the bl/ro wire that feeds into F23

3 - Then working back inside the car find the other side of F118 at T5g/4 on sw/gn - hook this into CCU loom at T10p/6 (goes to C2)


Cheers for now,

Paul

[S2central.net]

Dude you work far to quickly! I have all this kit for nearly 9 months or maybe longer now and haven't installed it

Right game on!

@Jamo - if you want to... could you send me that donor loom from an A4 so I can do some good detail on wiring 'how to' much like I did with the ABY conversions... so as to make it a little easier for folk to understand how to graft it into an S2 that already has manual aircon fitted.

I am looking for a loom locally to do this with, but no dice so far...

Upside for you will be having the guide completed in time for you along with a nicely labelled loom to make your conversion one step easier.

[Jamo]

I can send it yes, be handy as another member has a loom also looking to copy it.

What kind of timescales are you thinking here?

[S2central.net]

I could get it back to you next week if that works... I want to do it sooner rather than later, whilst I have all this shyte fresh in my head... don't want to have to learn it all again in 3 months time - LOL

[Jamo]

I can't pick up the loom until friday but can send it out next monday ( warning it's not fully stripped yet so it's all wires everywhere )

It's from a MY96 car and an older CCU than rjscotty

PM me the details for sending it out and I can arrange it

[rj scotty]

A little progress:

Got the outside temp and and sunlight sensors fitted




99% certain of have the wiring right now

cheers

rich

[rj scotty]

Progress

Thanks to Ben, mounting frame and face plate all fitted




Some simple trimming of the plastic required to get this to work.

Just awaiting the delivery of an earlier CCU now and the dash board can go back in.

Watch this space

cheers

rich

[S2central.net]

Just to follow up on a technical point made earlier in the thread... I was under mine today for a few minutes to try this.

Mine is manual aircon on the S2 and I wanted to check the logic for fan control. Sure enough, when A/C is turned on a signal is sent to ECU which in turn activates the afterrun pump relay (Aux 14) which in turn activates the lowest radiator fan speed relay (main #3). If you pull the afterrun relay then the rad-fan doesn't start when A/C is switched on.

I also discovered that when A/C is turned on, the cabin fan blows at lowest speed even if the knob is set to off - this ensures a certain amount of heat transfer across the evaporator. Fan blows harder when you turn the speed up of course. This is controlled by main relay #6 on the manual system.

[rj scotty]

Home straight !

Working Climate in right hand drive avant