A8 Parts Forum

A8 Parts Forum (https://forum.a8parts.co.uk/index.php)
-   D3 - Interior Electrics (https://forum.a8parts.co.uk/forumdisplay.php?f=46)
-   -   J255 Climatic Control Unit (https://forum.a8parts.co.uk/showthread.php?t=13803)

tc4332 2nd February 2018 05:39 PM

J255 Climatic Control Unit
 
Does anyone have an internal wiring diagram of J255?
Or does anyone have a faulty one that I can strip down?

tc4332 8th February 2018 09:27 AM

J255 Climate Control
This is the unit at the front where you can set the required temperature etc.
I want to connect to the contacts of the "ON/OFF" switch.
A non working one will suit me so that I can get inside it and see where two wires can be connected.

mattylondon 8th February 2018 09:48 AM

What project are you planning Ray?

There's a unit on ebay for £22.50. Other than that give A8Parts a call +++

tc4332 8th February 2018 10:09 AM

Morning Matt.
I have been using the Webasto to warm up the cabin on cold mornings. I have not added the water pump and pipes to install the full system.
On cold days I head out in slippers etc., open the car, press and hold the "ON/OFF" switch on J255 until the temperatures display. This fires up the blowers and Webasto. I can then lock the car and go back indoors.
Twenty minutes later I can go out to a defrosted, warm and toasty A8.
Now the project. Dah! Dah!.
I have a remote control sender receiver pair. The Rx has a relay with normally open contacts that I would to connect electrically across the contacts of the J255 On/Off switch. If that could be done then I could remotely set the Webaso etc. going from the bedroom, have a wash and the car would be ready for me.
Total luxury at up to now no cost!!!!
If no one offers a J255 I was planning on trying A8 Parts.
I don't want to break into my working unit until I have a decent idea of the problems that may arise. Even a circuit diagram of the internals would help.

mattylondon 8th February 2018 10:38 AM

I see what you are planning to do Ray.

Would adding the T90 Telestart to the webasto do the same job, or do you need the pump and pipes for the full system?

T90 Telestart (4F0909509 + 4F0909507B) is connected to the Aux. control module and in turn J255 via CAN. OEM albeit more expensive.

http://allegro.pl/sterownik-pilot-we...162265331.html £65 but with a VW fob. <--- Now Sold, someone on here?

tc4332 8th February 2018 12:17 PM

The days of being able to go out and buy whatever I wanted have gone.
The big effect of Gwen's illness is the loss of another income.
I have to watch the pennies!!!

mattylondon 8th February 2018 01:19 PM

Understandable Ray. Look after the pennies and the pounds will look after themselves. Let's hope you pick up a second J255 unit to investigate with. To note these do have component protection.

tc4332 8th February 2018 02:06 PM

Thanks for the heads up Matt.
I hadn't thought that CP would be involved, another silly expense if the unit is swapped out.
I was hoping that there would be a way of tapping in to the external wiring but of course with CAN BUS that is just wishful thinking. These cars are too technically complicated. Please bring back the days of just five basic circuits in cars.

mattylondon 8th February 2018 02:29 PM

Yeah CP is another expense you don't need. CAN BUS is great. It's the outdated clunky firmware that age these cars.

tc4332 15th February 2018 12:36 PM

Thanks to a very generous forum member I now have my hands on a J255.
VAG/Audi Number 4E0 820 043 A
SW 4E0 910 043 A 030

The unit was manufactured by Behr-Hella Thermocontrol GmbH (BHTC) in Lippstadt, Germany. This is not far from the Annual meet in Germany. I spent nine years in the area during my Army service and did know a lot of people there. Unfortunately the electronic guys thereabouts have moved on to a better place (this is the problem with age, everyone passes). I'm still in contact with their family members but none of them work for BHTC so no possibility of sneaking information through the old boys net.

Still can't find a circuit diagram but on close scrutiny I have found two small pads on the printed circuit board that I could solder two wires to. The plastic case has enough space for my remote receiver.
There are a number of openings in the case that two thin wires could pass through. I think this would be the better way to do this mod because the receiver aerial could be placed in a better reception area within the car.
I am a bit wimpish at the moment, it's cold outside, so I'll leave working on the car until later.

Big thanks to my secret donor.


All times are GMT. The time now is 03:38 PM.

Powered by vBulletin® Version 3.8.0
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.