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Discussion Starter · #1 ·
My heated mirrors have stopped working. I have checked the elements in the mirrors with a multi meter, they appear to be ok. The fuse is ok but there is no voltage at the connections to the heaters or at the fuse.

I have a copy of ELSAwin, looking at the wiring diagrams there are two ways they could be wired. The first is the mirror heaters are supplied via the rear window heater switch, the second is via a relay and fuse (already checked). Looking at the diagrams, it looks like mine are fed via the relay because they have the fuse.

I can't work out from the diagram where the relay coil is fed from, one side is shown as connected to ground, the other just goes to a box with an 8 in it. The wiring diagrams don't show any connection from the heated rear window switch to the mirror heaters or the relay[:cool:].

And to top it all off I managed to crack the mirror when I took it out to test[8o|]
 

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I think their might be something in the hand book about them only working when the adjuster is in the 0 position. I might be wrong.
 

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Discussion Starter · #6 ·
I think their might be something in the hand book about them only working when the adjuster is in the 0 position. I might be wrong.
....and the heated rear windscreen switch is on!
Mirror switch is in the centre position (0) and the rear window heater switch is on, still no volts at the mirror

Mine don't work now either... is there a fuse for the heater elements alone?
As mentioned in my first post, the mirrors can be either supplied direct from the heated rear window switch, sharing the same fuse/ supply diagram v1.

Have a look at the fuse panel, if there is a fuse in position 1 (red 10A) your mirrors are supplied via a relay diagram v2

Mirror wiring diagram v1

Posted Image


Mirror wiring diagram v2

Posted Image


Heated rear window switch

Posted Image
 

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Hey wait a minute...

"Mirror switch is in the centre position (0) and the rear window heater switch is on..."

Is this how it works? As I have only tried playing about with the (0) position L and R etc, havent actually played about with (0) + rear demister.... will have to try this.
 

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My heated mirrors have stopped working. I have checked the elements in the mirrors with a multi meter, they appear to be ok. The fuse is ok but there is no voltage at the connections to the heaters or at the fuse.

I have a copy of ELSAwin, looking at the wiring diagrams there are two ways they could be wired. The first is the mirror heaters are supplied via the rear window heater switch, the second is via a relay and fuse (already checked). Looking at the diagrams, it looks like mine are fed via the relay because they have the fuse.

I can't work out from the diagram where the relay coil is fed from, one side is shown as connected to ground, the other just goes to a box with an 8 in it. The wiring diagrams don't show any connection from the heated rear window switch to the mirror heaters or the relay
.

And to top it all off I managed to crack the mirror when I took it out to test
Just to explain the wiring diagrams...the 8 in the box means you need to go to track 8 on the same wiring diagram. If you look at the diagram yoiu posted - the box with the 8 is in track 17 (the numbers along the bottom).

So when you go to track 8 you will find a box with a 17 in it - that means these two wires are joined.

If you have a UK R32 then there is no relay for the heated windows.

The R32 mmirrors work though the Central Convenience System - you need to get the wiring diagram for that to show the circuit.

The heated rear windows only work with the ignition on and the Heated Rear Window switch is ON. In this case the mirror switch on the door has L-0-R (it can be in any position - the mirror heaters are only switched on by HRW switch)

The HRW switch sends a signal to the CCM. The CCM then sends a CANBUS signal to the electric window module in the door. Then the mirror heat power comes from the door module.

[:)]
 

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Discussion Starter · #12 ·
Thanks Graeme & Chris for the info; it kind of makes sense. I have been having a few issues with the CCM for a while, the electric windows, sunroof and interior lights have been misbehaving. Guess it could be linked??

Just seems odd that there is a separate fuse, which is why I assumed it used the relay etc. Just looking at the wiring diagrams for the door modules now to see if I can work out where to start faultfinding.

Think I'll first check the CCM is getting the "signal" from the switch, although I cant spot the connection from the switch to the CCM[*-)]

Why do they have to make it soooo complicated[:S] what's wrong with a simple switch and wire
 

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Discussion Starter · #14 ·
The signal from the HRW switch goes into T23/16 on the CCM to turn on the Heated Mirrors.
Thanks[Y]

Checked with VCDS today, the CCM is showing as faulty (been having some issues with the door locks today). However it is picking up the signal from the HRW switch. Going to take the door apart over the weekend to check the wiring etc..
 

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Discussion Starter · #16 ·
Digging up an old post-#kieran p
Did you resolve this issue - if so how did you do it?
I think it was a combination of the CCM having a hissy fit, and the connector on the electric window motors needed re-seating as the heaters are powered via the electric window motor…. I never really got to the bottom of it as they just started working after clearing the fault codes in the CCM and re-seating the connectors.
What ever it was they are still working today, I guess it was one of those MKIV electrical gremlins that pop up once in a while and disappear again.

I guess you have the same problem?
 
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