passanger side wing mirror heater

[Antowens]

hi everyone,
my passanger side heated wing mirror has stop working all the functions work to move it around up, down, left, right so on but the heater doesnt. I took it to a local garage and asked them to take a look while doing my front discs and pads, all he said in the report was no continuity on wing mirror. Now what does this mean as i have no clue does that mean i simply need a new glass or do i need a complete mirror or is it a problem on the wiring ????
thanks in advance any help appreciated as i am rubbish with electrics and so on

[fat controller]

No continuity means that the electrical circuit is incomplete, otherwise known as open circuit (think of it like a hosepipe, where the water represents the electrical flow - there is a break somewhere that is stopping the flow);

I'd guess that the most likely thing is that the element that lives in the glass has failed, but it could just as easily be one of the connectors that has popped off (they are typically just spade connectors); it could also be a fault with the wiring somewhere, but I'd investigate the easier options first.

Do you know anyone with a multimeter?

[gdallas]

i dont know the make-up of the circuit, but if the heater is on a different feed from the servos, then maybe try the fuse?

[s7gpt]

this happened on our last car, swapped the glass and everything was ok, easy job with a screwdriver and towel, think the glass is around £20 touch and worth a try ;)

[Antowens]

No continuity means that the electrical circuit is incomplete, otherwise known as open circuit (think of it like a hosepipe, where the water represents the electrical flow - there is a break somewhere that is stopping the flow);

I'd guess that the most likely thing is that the element that lives in the glass has failed, but it could just as easily be one of the connectors that has popped off (they are typically just spade connectors); it could also be a fault with the wiring somewhere, but I'd investigate the easier options first.

Do you know anyone with a multimeter?

ye i have a multimeter so best way to test would be take the glass off and put the meter across the two terminals ?? or i assume there is two little spade terminals one in one out ???

[s7gpt]

ye i have a multimeter so best way to test would be take the glass off and put the meter across the two terminals ?? or i assume there is two little spade terminals one in one out ???
Yep, 2 connectors ;)

[Antowens]

Yep, 2 connectors ;)

how does it come of with out breaking it hahaha must be a simple way to do it

[s7gpt]

how does it come of with out breaking it hahaha must be a simple way to do it:: a4mods.com :: - The Premiere Audi A4 Modification Guide and Pictures Library (http://www.a4mods.com/index.php?page=webcontent/pages/mirrors.html&category=3) this link gives a good idea :)

[fat controller]

It takes a bit of faith and a lot of bottle - the usual way to do it is to wrap a flat bladed screwdriver with cloth, and then work the screwdriver down behind the glass and use it to pry/pop the glass out. I warn you now, it feels a hell of a lot like you are going to break it (you might even manage to break it if you are unlucky).

If you get a short circuit (or as near as dammit a short) then the element is fine and your problem lies elsewhere. If I was a gambling man, I would put money on it being the element in the mirror glass being busted, or that one of the contacts has broken off.

[Antowens]

Thanks to everyone for there help i will have a go and if i break it loks like ill need a new one anyway hahahaha thanks everyone

[sportq]

I did this twice when I converted my mirrors housings to the brushed aluminium type.

Get a couple of PCI blanking plates for a PC and hook them around the mirror at the 3 and 9 o'clock postions and the push your thumbs onto the glass in the same place and then pull with equal force on both sides.

Peter

[Antowens]

Well gave this a crack today and good news i got it off without cracking it woooo got a replacemnet from audi to the tune of £36.00 when i took mine off it happened to be a dimming mirror with a plasma cell in it or something the fella at audi said to replace it it would be £170 i later found out my car didnt come with a dimming wing mirror option so the £36 one was the right one so i now have a dimming mirror with a broken heater and no use for it hahaha dont know why someone would pay that much to put one in and not have it working

thanks for all the advice and help everyone

[sportq]

I forgot to mention above that my driver side mirror wasn't working so I was out last night (3C!) pulling the mirror off to check.

If anyone else finds this thread here's how to check them, you'll need a voltmeter with a resistance range (0-10 ohms is enough) and optionally a 12v, 3A power supply. With the meter on ohms, the resistance across the two terminals should be around 5ohms. I had to push down hard on the terminals with the probes to get a consistent reading. I compared with the passenger side which was known good. You can also check by hooking it up to a 12v power supply that can deliver at least 2.5A, doesn't matter which is positive and which is negative it's just a resistive element. It should get warm within 10-20 seconds.

It turns out the heating element was fine the connector must have been loose or not making good contact from when it was re-fitted after chaning to aluminium mirror housings.

Peter