Tracing and repairing a faulty heated rear window/heated mirror

[ozfrog]

First thing, I'm not sure where to put this, so it is here in the Peugeot forum because the problem is with my 307. I'm sure that it will be moved to the correct forum by an ever-vigilant moderator.

Neither the driver's side exterior mirror nor the heated rear window of my 307SW are heating. The passenger side exterior mirror is heating. Tracing faults like that are beyond my pay grade, so off to the auto electrician I went last week.

They tested what they needed to and found that power was getting all the way to the mirror and to the heated rear window. But still neither was heating up. They left it at that, suggesting that I get a replacement rear window(!) and a replacement exterior mirror.

When I went to collect the car, they told me that they were not prepared to take off the mirror and risk breaking it because I wouldn't be allowed to drive the car out of their workshop without that mirror, and they were 99% certain that I wouldn't be able to get one that day. They were correct about not being able to get a replacement mirror that day. I haven't found one even 5 days later, despite many being advertised on eBay and Gumtree. However, I don't think they looked very hard to find instructions for removing the mirror because I found a set of text instructions for removing the mirror glass almost immediately after I got home.

When I showed them the removed mirror glass today, they pointed out that one of the connectors was rigid, but the other was floppy. This, they suggested, meant that the connector had probably broken away from the heating wires on the back of the mirror glass.

As far as my skills go, I can't see a way of separating the plastic backing from the mirror itself. The parts book excerpt I've attached shows that Australia gets its own version of the driver's side exterior mirror, but unfortunately, I can't find an image of the reverse of the mirror glass that has the plastic mounting or backing. If anyone has seen the reverse side of the mirror and knows what I'm talking about, I'd be interested to know if you think it is possible for that plastic backing to be removed. Or am I on a wild goose chase?

Now the rear window! Is there an easy method to find which strip across the rear window is broken? None of them appears to be broken with the naked eye, and my eye surgeon said that my vision is as close to 20/2o after my cataract removal!

[mickthemaverick]

This diagram may give you an idea:

https://ultimatestyling.co.uk/peugeot-3 ... -ult432-mg

[PaulC5]

For the rear window it might be more than just a strip that is broken as when I had this it was just the one or 2 strips that did not heat up, not all of it. You could look at each strip shining a torch through but it could be the connector part that needs attention. When they were checking did they check the supply and earth side of it or just for a supply ? It also needs a few amps supply, not just for a voltage or continuity which a part broken wire would pass and appear ok.

[ozfrog]

When they were checking did they check the supply and earth side of it or just for a supply ?

They specifically mentioned that they had tested both sides.

For the rear window it might be more than just a strip that is broken as when I had this it was just the one or 2 strips that did not heat up, not all of it.

I’m no electrician, but doesn’t that depend upon whether the strips (the system) are wired in parallel or in series?

To demonstrate that I’m no electrician, I don’t even know if such a system (a heated window) can be wired in series.

You could look at each strip shining a torch through but it could be the connector part that needs attention.

Does this trick work in the dark only?

Maybe I’m giving them too much credit, but if they tested both sides of the window, surely they would have noticed if the connector(s) were the problem?

It also needs a few amps supply, not just for a voltage or continuity which a part broken wire would pass and appear ok.

Again, maybe I’m giving too much credit to them, but surely they should know something so ‘basic’?

[ozfrog]

This diagram may give you an idea:

https://ultimatestyling.co.uk/peugeot-3 ... -ult432-mg

I’m not sure what diagramme you’re trying to show me, Mick. The link took me to a website where they sell spare parts, including the mirror for my car. I’ve just been chatting to the sales person using the chat feature on the website.

Not the most helpful person I’ve ever encountered in my life!

Eventually, I was given the link to their eBay store because they, ultimate styling, do not export anything. I was told that if my country was on their approved list, I would be given shipping options.

However, even though the mirror I need is on their website, it is not available in their eBay store. A similar mirror is available, but it is more than 6 times the price of the one on their website. I don’t think I’ll be purchasing the mirror from there.

[mickthemaverick]

Sorry Andrew, I should have said picture, not diagram. I was responding to your question in your post:

If anyone has seen the reverse side of the mirror and knows what I'm talking about, I'd be interested to know if you think it is possible for that plastic backing to be removed. Or am I on a wild goose chase?

and intending you to see this:

The back of your mirror

[CitroJim]

I'm a bit late to the party on this one but it seems to me the auto-electricians did not thoroughly test - as you allude to Paul...

Simple resistance tests on both the mirror and heated rear window and voltage checks under load and earth integrity tests would have isolated the problem(s) accurately and from what I can see, these were not carried out. This is all very basic auto-electrical work.

Heated rear windows rarely fail completely and usually just loose a 'line' or two. So often, the wiring to it (or it's control circuitry) is unhappy and likely a high resistance somewhere, especially the wiring from the device to the car body (earth). Fundamental stuff to test. A high resistance connection can show full voltage off-load when tested with a meter but show no voltage under load due to the aforementioned high resistance somewhere.

I'd be inclined to engage a different auto-electrician although I do appreciate they're a rare and endangered species these days...

[ozfrog]

Sorry Andrew, I should have said picture, not diagram.

That makes more sense to me, thanks.

If anyone has seen the reverse side of the mirror and knows what I'm talking about, I'd be interested to know if you think it is possible for that plastic backing to be removed. Or am I on a wild goose chase?

and intending you to see this:

Il was very negligent of me to not put in the image of the mirror. Thanks for inserting it.

And the question still remains for anyone to answer.

Prices in Australia for this mirror are varied, but can be as high as $275+postage I think is the ‘best’ I’ve seen.