Heated windscreens

bretti_kivi

Member
I see the biggest issue as power. You're talking about 1kW or so? Make it 1.2 for ease of calculations - that's 100A. 1.4s only have a 90A alternator.
The 1.0TSI Octavias here aren't offered these days with heated windscreens for this reason: too little power from the alternator, too much strain on the internal systems as a result and significantly higher consumption because so much power is going to the electrical system rather than motion. There's a reason the alternator was upgraded to 140A in the 90 TDIs, also to do with the PTC element. Which is another 1.5kW IIRC...

- Bret
 

GPW

Member
Hello all,

Further info.

Manufacturer guarantees a perfect fit.
Post to any uk post code is £47 + vat
If you have to replace your heated screen due to damage/crack then there would need to be another minimum order of five as there is no regular demand to justify keeping them in stock.

I propose that if there is enough interest to make this a go I would supply people with the company details so that each person deals directly for payment etc. That then takes me out of the loop.

But they would not make any screens until there is a minimum of five orders.

Thanks.
 

GPW

Member
Found this wiring diagram https://www.heatedwindscreen.com/acatalog/wireing_details.html

A big negative is it's gonna be annoying if you pay a lot out for the windscreen plus the wiring etc if it were to get broke within a few months when there's a minimum order of 5. Plus any replacement covered on your insurance is just going to be for the original spec
That's a very basic standard relay circuit. But yes. I would want something resembling OEM which would be simple plug and play.
 
Hi, Looking at the diagram it gives 25a or 35a can you check what it would be? Where on the screen does the wiring enter/exit?

I like the sound of the idea
 

GPW

Member
Hi, Looking at the diagram it gives 25a or 35a can you check what it would be? Where on the screen does the wiring enter/exit?

I like the sound of the idea
Hi. I have been told it will be a 25 amp system. We can request the wiring enters the car on either the N/S or O/S. I was thinking N/S so to make life easier.
 
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timmus

A2OC Donor
Hi folks,

Sorry it's taken me a little while to get involved in this, despite the PMs and tagging in this thread.

We can request the wiring enters the car on either the N/S or O/S. I was thinking N/S so to make life easier.
For a right-hand-drive car, the wiring should be on the N/S, but we're probably best talking about this in terms of left/right. The wiring should enter the car on the left, as the under-floor electronics compartment is always on the left, irrespective of whether the car is a right- or left-hooker. If I was wiring such a system for A2 owners, that's where I'd be doing it.

I see the biggest issue as power. You're talking about 1kW or so? Make it 1.2 for ease of calculations - that's 100A. 1.4s only have a 90A alternator.
Whilst we now know Bret's power-consumption figures are a bit high, I still think he makes a valid point. A 25A current draw isn't negligible, especially not on A2s with the 90A alternator. Even on A2s with more beefy alternators, a cold, dark morning could see the driver asking for the electric cabin heater, rear screen heater, headlights, heated seats, etc. Throw a heated front screen into the mix, and the alternator may be on its knees, begging for mercy. This is probably something that needs thinking about on a car-by-car basis, depending on which engine/alternator/options are fitted.

That's a very basic standard relay circuit. But yes. I would want something resembling OEM which would be simple plug and play.
The wiring diagram posted above is, more or less, how I'd envisaged wiring this in. As far as I'm aware, the goal here is to make it such that the front winscreen switches on/off with the rear screen demister rather than it having its own dedicated button. I can certainly do it with OEM relays, connectors, etc, all located neatly in the proper relay plates, meaning it would all look factory standard, but I cannot see a way of making this plug-n-play. If I'm to be involved in this, then the electrics would have to be installed by me, in much the same way as I'd do any of my other retrofits.

A big negative is it's gonna be annoying if you pay a lot out for the windscreen plus the wiring etc if it were to get broke within a few months when there's a minimum order of 5. Plus any replacement covered on your insurance is just going to be for the original spec
This is, of course, a big consideration. The issue regarding windscreen insurance could probably be circumvented by having a chat with the insurance company and insisting that any future screens are sourced from a particular supplier. However, who is that supplier? Does an A2OC member stock replacements? If so, where? How many? What happens when the supply dries up?

if your wear glasses the fine wires can cause issues
I suppose this is a personal issue and not really a deal-breaker for all, but I absolutely hate driving vehicles with electrically heated windscreens, despite not wearing glasses. I'm often distracted by the weird, diffractive effects that seem to be caused by the matrix of fine wires, especially when driving at night. I'm always keen to see new developments for the A2, and I'm happy to be part of the overall machine to make this happen, but my own A2 will remain demisted by old-fashioned hot air!

Cheers,

Tom
 

GPW

Member
Many thanks for your input Tom. Excellent as always. Would it be possible to wire it in such a way the when the heated screen is on the auxiliary heater cancelled incorporating the Eco function? On our Yeti the heated screen clears easliy within 5 minutes. When the front screen switches off the auxiliary heater cuts back in. That would cut down on the alternator load. Just a thought.
A heated screen is a personal preference. I drive our Yeti regularly without any visual disturbance.
 
Thanks Tom for your input.
I regularly work work early mornings and 12hr shifts and i've been scraping the car both am and pm. With a dirty diesel and webasto running it still takes some time for a clear windscreen and sitting about in the car park, so still keen. Daughter had a Fiesta with one, never noticed the wires but loved the quick defrost.

Are larger output alternators available? Is the A2 fitting pretty standard?
 

timmus

A2OC Donor
Would it be possible to wire it in such a way that when the heated screen is on the auxiliary heater cancelled incorporating the Econ function?
I'd have to have a look at the wiring diagrams to see whether this is possible. It could be that the ECON button is purely sending a digital instruction over the CAN network and is therefore inaccessible to analogue electronics. I don't have acess to the wiring diagrams right now (I'm typing on my sister's laptop, and she's not a big enough A2 geek to have them installed, despite owning an A2 herself). :)
 

2work

A2OC Donor
I too am really interested in this venture. It is something most cars are missing these days and would prove useful to save 5 minutes in the morning when Jack Frost has been out.

Before I was to commit money to a heated screen I would need to know the additional cost of parts and work associated to having it working without electrical problems.

Whilst the manufacturer is refining the design and timeline etcetera are you able to find out the worst case costs for the appropriate powered alternator along with offline discussions with Tom to get his thoughts on fitting price, as I can only assume this is something many of us would only allow him to do. His reputation proceeds him and I couldn’t think of allowing anyone else to play with the electrics on my car. Mainly as he would understand the difference between the power demand of standard fitted accessories verses the extras retrofitted by himself or others.

This really is an exciting project which I feel you could sell but before I was to open my tight wallet I would need to know what additional cash I would need to have this fully operational. I’d hate to spend hundreds on a windscreen and have it sat in the garage with no idea if it will ever be of use.

My feeling is that you will get a definitive answer from Forum members once you're able to offer a clearer understanding of full up cost from purchase/delivery to being able to turn it on, on a cold morning.

These are just my thoughts and I must say hats off to you as this really is an amazing idea.

kind regards,

Tom
 

ChrisA2

Member
Hi everyone I’m new to the group and have been made aware of this post, I’m a professional windscreen fitter with 15 years experience.
Just to answer a couple of questions I’m based in Leicester. PM me regarding charges to fit a screen.
The heated screens have 2 separate connections one on the passenger side one on the drivers side so the screen is basically 2 halves and also sometimes have an earth strap that bolts to body or under the headlining.
 
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