Originally Posted by MP4.2+6.0

With old post and new replies, I'm not 100% sure of what the questions are....

Originally Posted by MP4.2+6.0

With old post and new replies, I'm not 100% sure of what the questions are.

From my C5 experience where I had one that broke, I thought about going the other way actually--toward a glass panel. Regardless of preference, be sure to look carefully at exactly what the parts are. As I recall, where it got tricky was the sunshade movable panel first of all. That panel travels on its own little track, while the solar one is attached directly to the roof panel. I think you may need to change the whole roof cassette (and buy it as such from a junk yard). That means the whole track assembly and everything. If you buy at a distance, you will find shipping for it is somewhat pricy too-- big bulky part once it is the whole cassette.

Then after you get past the whole shade issue, you are going from a roof panel with no solar panel to one that of course now produces power. On the C5 the electronics for the voltage converter were on the bottom of the panel. The panel connected electrically to the car body and harness by a couple of contacts on the edge of the panel and sunroof opening. BUT, if you think about it, you still need the wiring from the panel to the blower motor. I think again those contacts built into the panel AND opening will mean you need the whole cassette and not just panel itself. Since D4's (and 3's) have custom harnesses based on how the car is equipped, I don't think you will find the wiring in place either, so you have to retrofit from the roof to the blower, AND do what ever tie ins are necessary (probably some kind of relay/control box), since of course roof runs fan intentionally while car power is off, while heater/HVAC fan runs normally only when it is on.

Last, if I haven't talked you out of it yet, check the D3 board. There are now a rash of blower motor failures. The common theme in all of them is solar roof. See this thread: https://www.audiworld.com/forums/a8-...motor-2840964/ My same experience on my C5 A6 by the way with it--I had to replace the blower fan along the way. Seems to happen with fan operating many more hours per day than just driving, plus it is operating with air hot instead of cooler like cold days or with A/C. Honestly, I don't think Audi thought this part of the design through, and the failure rate is proving it out. Thus, if you either have or retrofit a solar roof, expect to pay twice: once for the option, and then again by ten years when the fan fails. From a fellow AW'er who just had his done, it cost him $1200 to have an indy shop do it, about ⅔ of the cost being the blower. There are brushes available for it (if that's the failure), but that is deeper DIY stuff than many ever do.

Net, I had it once, but found I liked the roof light with shade open. Now that I see it often seems to cause the heater fan to fail in the long term, I am affirmatively avoiding it when possible in used D4 searches.

Originally Posted by iloveandhateaudis

..hmmm interesting on the solar panel roof. I (loose use of the word...I meaning "I sort of helped someone who knows what he's doing take everything apart and replace it") replaced the blower motor about 6 weeks ago, bought a used one that 'tested good'. It worked perfect and just the past 2 days started slow...made some whining noises, and basically exhibited the same symptoms the other one did as it went out over a month or so. Not sure where to go form here.