Your solar sunroof experience
 

Installed sunroof today from German donor car and never noticed how the sunroof is actually working.

I assume if I just sit in the car with ignition off it should start working immediately. Is that correct?

Is it noticeable at all? What is your solar sunroof experience?

If it's sunny it works until you turn the ignition on.
Just get in the car and you should hear and feel the fans "wafting" quietly with a speed that varies with the suns power.

Does the HVAC need coding for it as well as the wiring, or is it just a relay?

Never coded anything :)

Installed relay that toggles blower motor feed between 'the sunroof' and 'the battery' depending on 'sunroof request' wire that is connected to HVAC unit.

I will check this week hopefully these is more sun.

Mine was fairly active yesterday when I went to get something from the car.
Is this an early or late model panel?

I notice that my FL S8 with the later panel is much "livelier" than my PF was with the earlier design.

As an aside, I had been wondering whether to fit a cutoff switch so that it only operates on days when I want it to, usually when out for the day and parked in the sun.
Would that be relatively easy and where/how would you do it, presumably in the control circuit?

I have late model panel with 4 courses of cells.

You can easily install switch that will simply cutoff the "+" wire from sunroof before it enters the relay. I'm going to install that switch later, but will use it to toggle between trickle charging mode and blower mode :)

You can hear mine running on a sunny day. A switch is a good idea, cos they're not so good when it's cold and damp (but sunny) as it tends to mist up the car a bit.

Mine is whispering away right now; 9am and sunny though only 3C so rather pointless.

If you're not convinced it's doing anything you could shut all bar one of the vents to try and increase the flow of air to that one vent?

Is that just a low-power control signal and would that be a good circuit for a switch? Where does it run?

The panels, even the later 4 panel version, dont make the fan run particularly fast.

In very strong sun light, you will hear it running. In not so bright sunlight it might not be obvious at all, however it will still be trickling a bit of airflow, which is the whole point.

For testing, if you remove the cover for the blower motor under the bonnet, it is often easier to see the blower motor turning, than trying to feel or hear it +++

Cheers guys. Bright sun today. Sunroof works beatifully.

You can clearly hear vents rotation and powerful breeze cools the car.

I'm already thinking about the On/Off switch to the trickle charger +++

If understood the ELSA scheme correctly: The HVAC unit connects the 'solar request' wire to ground when it wants to energise the relay and switch blower motor power from solar to battery (kind of when ignition is ON, but decision making can be more complicated). All other time solar request wire is in disconnected state (car is parked doing nothing, relay is de-energised) and blower motor is connected to solar element.

OK, that sounds a bit more tricky then if "solar power" is the default.
Sounds like an isolation switch would need to be in the main feed from the panel; how "meaty" is that?

>> OK, that sounds a bit more tricky then if "solar power" is the default.

Blower motor is fed by solar power when relay is not energised and car is parked. Relay can't be in energised state if car is parked as the battery will be drained that way.

>> Sounds like an isolation switch would need to be in the main feed
>> from the panel; how "meaty" is that?

Medium meaty -- 2.5 sq.mm.

It can be mechanical switch or it can be another relay. In case of relay we want the 'impulse relay' (=dual state relay). That means a relay with two steady states: A and B. You only need an impulse to switch it from position A to position B and then back again with another impulse. We don't want a classic relay that only connects to alternative position as long as constant current is applied (energised state) as we want two alternative positions A and B both available when car is parked, which means relay cannot always be in energised state (=battery drain mode).

So, a mechanical switch rated around 15A should be OK. Any idea how much the sunroof can get up to in the real world.

>> Any idea how much the sunroof can get up to in the real world.

Don't understand the question.

Power rating of facelift sunroof with 4 courses of cells is 33.6 Watt if this is what you're asking.

That will do, thanks. +++
I was probably (bad wording) asking what current it generated connected to the fans. From that I'd say it can only be a handful of Amps at most.

I'd also guess it won't be getting as high as 12V but whatever current/voltage is seen in practice won't need a massive capacity switch.
I'd guess that the main reason the cable is relatively thick is to keep the circuit resistance to a minimum.

I've got rocker switches rated at 10A/250V so that would be fine. Roughly where does the cable run and is there an obvious switch location you'd suggest?

I've just had a look at this thread, with IT's "electrickery" explained in detail: http://forum.a8parts.co.uk/showthread.php?t=5370
From that there seems to be a connection in the earth lead from the sunroof that would be ideal for looping in a "cutoff" switch, though no good for battery charging.

Blame my English as second language skill!

10A switch is more than enough.

Look at this thread and open pictures:
http://forum.a8parts.co.uk/showthread.php?t=5370

The cable where you need to install switch comes to the centre of relay baseplate. If you think of baseplate as a 3 by 3 checkerboard the wire you need arrive exactly in the middle of the baseplate.

On pictures it is red 2.5 sq.mm. cable which runs in a conduit with another ground wire which ends with yellow connector.

Please be aware that your baseplate will most probably be yellow and not red as you have facelift car.

You can install switch anywhere you want if you just extend wire in the place where you cut it for the switch.

Now you've done yours Servey I'll have to bring mine over lol

How long do you reckon it took you first time and would it be quicker 2nd time round?!

Thanks, I think we posted the same links around the same time.
Looking at the layout, I think an easy option is a short loop of wire to a switch clipped on the transmission tunnel trim panel but hidden where it's only accessible with the glovebox popped open.

It took me roughly whole day to do it properly. But I had small setback when one contact of the sunroof snapped off because of tired plastic and I had to repair it in a way it won't break any more.

Also, I didn't pry off the A pillar trim to snake the wires this time, because the last time I was routing microphone into the rear view mirror area I've put some meaty wires there for 'future extensions', so this time I just reused the wires, so it saved some time too.

There is no need for second person to remove old sunroof and install new sunroof. If you bring totally prepared car with all parts I can guide you no problem.

The torque you mentioned for some bolts are not important I think.

I think you can also install the switch inside that small compartment in the knee panel. It will be easier to reach there and it won't be visible. I already use that space for AMI (http://forum.a8parts.co.uk/showthread.php?t=7109), but there's still plenty of space for a switch.

Yes. This is correct. The logic almost follows the same as ignition on/off with the exception of the resting heater. If you want to run the resting heater, which works with the ignition off, then the fans must be connected to the battery, not the solar panel. To the best of my knowledge this is the only reason the relay is controlled by the HVAC unit and not the ignition state.

It is also slightly unusual in that the HVAC unit grounds the relay, rather than providing a +12 feed to it as you rightly state +++

I wouldnt get overly excited about a bypass switch as the incredibly rare occasion when its both wet and very sunny and a tiny bit of moisture gets in the car, if your A/C is working correctly it will sort it out in seconds.

Likewise, the concept of using the solar panel to trickly charge the battery i find dubious as the power output is so relitively low, and the battery on the A8 so very good. If you find you //need// to trickly charge your battery, it likely needs replacing or you have a current drain you shouldnt have....

Of course its all good for novelty value if thats your priority +++

I'm rapidly filling that up with other stuff (XcarLink, Bluetooth, A/V interface, DVB-T for starters) and also don't want to add any more wires to it; fitting it back is going to be tricky enough as it is. :(
And the glovebox is on the "right side" (left) so that I can do it easily and independently of these.

Thanks for recommending me this upgrade Ian -- I remember I hesitated as my car is light blue colour, almost silver colour, and I was concerned that solar panel won't look good on it. But you said that it will be such a talking point on light colour car. So I made the upgrade and you're right -- this is such a talking point!

Novelty!

I need to have my 110ah battery always charged to the brim as I have installed heated windscreen last year. When HVAC unit sends heating request to the monster transformer in the boot it also starts to measure the voltage on the battery. Measuring voltage allows HVAC to abort heating process prematurely if voltage drops below acceptable levels to avoid draining battery completely. To have long and effective 'heating session' on D2 we need two things: 1. 110ah full size battery; 2. fully charged to brim battery, so it'll keep proper voltage for extended periods of heating.

Here is the solar charger device from the company which makes the best trickle charges in the world:

http://www.ctek.com/gb/en/chargers/D250S%20DUAL
http://www.ctek.com/Archive/ProductP...%20DUAL_EN.pdf
http://www.ctek.com/Archive/ProductM...%20DUAL_EN.pdf

Yes, it will take forever to charge drained battery, but 30W+ of power is enough to top up battery from 90% to 100% during several hours of UK sunshine. And that 10% creates the difference when heating. At least I believe so ... :) :) :)