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Swapping radio and climate control help

Discussion in 'A4/A4 cabriolet/S4 forum(B6 chassis)' started by bucks_a4, Nov 20, 2009.

  1. bucks_a4
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    bucks_a4 Member

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    Hi guys
    need some help quickly if possible, long story short, my buttons on my radio and my climate control have been scratched/rubbed off, common problem i think, not a huge issue, but my dad has a company b7 a4, which he is giving back next week, and they have agreed to swap my parts over for the ones in his as his are newer and identical to mine ( i think, both radios and climate units look identical), so im gonna get the newer ones out of his.
    Anyway, shouldnt have a problem removing the radio, gonna get the tools tomorrow, but is the climate control unit in the b6/b7 just clip in/out or is it screwed in, and if so, what type of screws are they?

    Thanks very much, be good if someone could let me know before tomorrow morning.
    Cheers
    #1
  2. no_idea
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    no_idea Member

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    I think you will find that the B6 & B7 climate units are different. I believe to fit a B7 one in a B6 you need an extra relay for the rear screen demister.
    Can someone verify this?
    #2
  3. bucks_a4
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    bucks_a4 Member

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    ive searched but cant find any references to it, if someone could confirm or deny that would be good
    Thanks
    #3
  4. Woorlord
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    Woorlord shifting to Hyperspace... .

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    Any B6/B7 A/C unit requires coding to the car VIN - talks to the Instrument cluster for security - I guess to stop people nicking and swapping these easily removed items as they will just pull out!!
    A/C removal - Single DIN is a doddle - just pull it out. Double DIN - I had to pull out & remove the radio and then I could pull out the A/C unit - Auto transmission lever needs to be pulled back twoards the handbrake first. Both instances no screws - they should pull out enough to remove the cables.

    VIN coding of the A/C unit can be done through VAG-COM - do have the procedure somewhere if required.

    A B7 A/C unit will not work the Rear demist circuit and does require a wiring loom modification with a 30A relay to get it to work. Thought I'd posted the modification but can't find it but have the text which is pasted below..............


    .............With the RNS-E out this gave me access to the "newer" A/C unit I had installed when going from Single to Double DIN.

    After mod. Rear Demist now comes on and the rear glass definitely gets warm - although I do notice that the relay pulses on and off and then on, say every 2-3 seconds. No errors with VAG-COM. Maybe it's the outside temperature being 20+ degrees? VAG-COM does register the relay switching on and off through monitoring the A/C unit, "channel 012", I seem to recall.

    Can't seem to get the heated wing mirrors on - but think they do not come on unless outside temp is 5 degrees or less. Today is 20+deg. They are actually controlled via the individual door modules - probably over CAN-BUS and not with this heated rear window circuit.

    Modification:

    Required for A/C units where Rear Demist is controlled by slave relay and not directly by internal switching of A/C unit. Bentley circuits suggest A4 models "from November 2004". I can confirm this mod is required for A/C unit part no. 8E0 820 043 BM.

    The mod. was pretty straight forward and required a four "blue" female spade crimps, a short length of 1.0mm wire and a 12v/30A automotive relay.

    Pull fuse F26 - Heated Rear Window - for safety!!

    Pull all plugs from A/C unit.

    Sourced a ground of A/C connector D13 - removed the hood casing - Soldered a wire here inside the plug and then remounted the casing. Terminated the free end in a female spade connector and this wire goes to the relay coil.

    Undo the taped loom wires to connector "F" - you need to pull back the tape around 2~3inches.

    Cut 4mm wire F6 (White/Lilac) around 1.5 inches back from "F" connector.

    • A/C end - soldered a "thinner" wire to this and terminate in a female spade connector which then goes to the relay coil. This is the control signal.
    • Car end - put a female spade connector on which goes to one side of the relay switch terminal. This is the feed to the heated window element.
    Cut 4mm wire F5 (White/Yellow) around 1.5 inches back from "F" connector.

    • A/C end - insulate as no longer used to supply 12V/30A to A/C unit.
    • Car end - (From fuse 226, i.e. Large 30A Fuse in position #26). Put a female spade connector on and wire goes to other side of relay switch.
    Re-taped all looms with PVC insulation tape.

    Refit all A/C unit plugs.

    Refit Fuse F26.

    Mod. Complete.

    I also cleared any DTC errors with VAG-COM - I tested at various stages to see if relay switched and the rear demist light would stay on before connecting the 12V/30A power feeds! Just to be 100% sure it was going to work!!

    Hope this helps.

    #4
  5. bucks_a4
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    bucks_a4 Member

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    right, thanks for that, im not gonna be doing that, havent got the time for all that, i assume the radios are just interchangeable providing i have both codes? maybe i will try to replace the buttons on the AC unit instead.
    #5
  6. Woorlord
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    Woorlord shifting to Hyperspace... .

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    Here is the complete process as described above BUT with relay terminal numbers indicated for a standard 12v 30A Automotive relay, typicsl relays shown at this site Relay Schematic Here, you can use a 4-pin or 5-pin relay as terminal 87A is not used here.

    Relay coil is across terminals 85 & 87,
    Relay switch Common is terminal 30,
    Relay switch Normally Closed is 87A (No coil voltage and relay switch is connected normslly between 30 & 87A),
    and
    Relay switch Normally Open is 87 (apply 12v to make relay contact between 30 & 87)

    ---------------------------------------------------------------------------------------------------------------------------------

    Any B6/B7 A/C unit requires coding to the car VIN - talks to the Instrument cluster for security - I guess to stop people nicking and swapping these easily removed items as they will just pull out!!
    A/C removal - Single DIN is a doddle - just pull it out. Double DIN - I had to pull out & remove the radio and then I could pull out the A/C unit - Auto transmission lever needs to be pulled back twoards the handbrake first. Both instances no screws - they should pull out enough to remove the cables.

    VIN coding of the A/C unit can be done through VAG-COM - do have the procedure somewhere if required.

    A B7 A/C unit will not work the Rear demist circuit and does require a wiring loom modification with a 30A relay to get it to work. Thought I'd posted the modification but can't find it but have the text which is pasted below..............


    .............With the RNS-E out this gave me access to the "newer" A/C unit I had installed when going from Single to Double DIN.

    After mod. Rear Demist now comes on and the rear glass definitely gets warm - although I do notice that the relay pulses on and off and then on, say every 2-3 seconds. No errors with VAG-COM. Maybe it's the outside temperature being 20+ degrees? VAG-COM does register the relay switching on and off through monitoring the A/C unit, "channel 012", I seem to recall.

    Can't seem to get the heated wing mirrors on - but think they do not come on unless outside temp is 5 degrees or less. Today is 20+deg. They are actually controlled via the individual door modules - probably over CAN-BUS and not with this heated rear window circuit.

    Modification:

    Required for A/C units where Rear Demist is controlled by slave relay and not directly by internal switching of A/C unit. Bentley circuits suggest A4 models "from November 2004". I can confirm this mod is required for A/C unit part no. 8E0 820 043 BM.

    The mod. was pretty straight forward and required a four "blue" female spade crimps, a short length of 1.0mm wire and a 12v/30A automotive relay.

    Pull fuse F26 - Heated Rear Window - for safety!!

    Pull all plugs from A/C unit.

    Sourced a ground of A/C connector D13 - removed the hood casing - Soldered a wire here inside the plug and then remounted the casing. Terminated the free end in a female spade connector and this wire goes to the relay coil, terminal 86.

    Undo the taped loom wires to connector "F" - you need to pull back the tape around 2~3inches.

    Cut 4mm wire F6 (White/Lilac) around 1.5 inches back from "F" connector.

    • A/C end - soldered a "thinner" wire to this and terminate in a female spade connector which then goes to the relay coil, terminal 85. This is the control signal.
    • Car end - put a female spade connector on which goes to one side of the relay switch terminal 87. This is the feed to the heated window element.
    Cut 4mm wire F5 (White/Yellow) around 1.5 inches back from "F" connector.

    • A/C end - insulate as no longer used to supply 12V/30A to A/C unit.
    • Car end - (From fuse 226, i.e. Large 30A Fuse in position #26). Put a female spade connector on and wire goes to other side of relay switch, terminal 30.
    Re-taped all looms with PVC insulation tape.

    Refit all A/C unit plugs.

    Refit Fuse F26.

    Mod. Complete.

    I also cleared any DTC errors with VAG-COM - I tested at various stages to see if relay switched and the rear demist light would stay on before connecting the 12V/30A power feeds! Just to be 100% sure it was going to work!!

    Hope this helps.
    #6
  7. simon.m
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    simon.m Active Member

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    i have a a4 b6 and have just put a cd player in from a 2006 with no problems what so ever.
    but not sure if 2006 is a b7 or not
    #7
  8. Woorlord
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    Woorlord shifting to Hyperspace... .

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    It's not the CD player that's the problem - it's the A/C (Air Conditioning) unit from a B7 into a B6!
    #8
  9. simon.m
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    simon.m Active Member

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    hey mate yes i see that but i see he said about the radio too so just let him no that will go in with no problems
    #9
  10. mattyboyc
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    mattyboyc Active Member

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    The easiest thing to do is just swap the fronts, i bought a brand new faulty one off ebay when i did my single to double dinn conversion as it had to be shaved down on both sides to fit the console, but if you only want the buttons remove both units undo the torx screws on the back the front then clips off, put the good one on your unit and the worn out one on the company unit, job done,

    Matt
    #10

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