Either way, skip the solar package. IMO, simply not worth it for too many reasons to list. My next 3G on order will not have it.
My solar works great in Phoenix. I leave it on all the time. It automatically cuts out when the car starts. It does not appear to have an upper cut off temp. It really works well keeping the interior temp much lower than otherwise. The remote air is just as great.
The output power of a given solar panel is almost solely controlled by the amount of light falling on the panel not the ambient temperature. As was pointed out by Carz89, colder temperatures produce more power from the solar panel not less. A higher temperature panel typically will produce less power. But this temperature effect at any human survivable temperature is small. Remember the panel converts photons into power at an efficiency determined by the panel's construction. More photons in more power out.
I can verify that if the button is depressed the system is always on. There is VERY little visual difference between the button being on or off, I had to push it a few times to be certain it was on. Other than that, one of my all-time favorite options and very well worth it. If available I would buy it on any car I buy in the future.
I am now convinced mine isn't working. I have kept the button depressed ALL the time. When I get in the car I can hear a fan running and feel hot air coming out of the vents. It cycles on and off every 5-10 seconds and continues to pump out hot air until I turn on the car. My body temp is give or take 98° and EVERY time I feel the air it feels hot (at least hotter than 98° if it feels warm to my skin), which means there is NO way it can be cooling the interior to anything close to ambient tempature. I have also hesitated using the remote a/c because then I can't tell if the solar venting is working. I am kind of caught between a rock & a hard place.
If it's "blowing", it's working. The air will feel hot if it's hot outside. What I have noticed, however, is if you're parked in any sort of Southerly direction, the solar gain on the black intake grille below the windshield does preheat the incoming air which offsets some of the cooling effect. That being said, try disabling the system and note whether the car is any cooler. Also - there is much to be gained by using a HeatShield in tandem - I've done this and it makes a world of difference.
Hmm! Perhaps it's a silly question, but how long have you waited each time? The manual says that after depressing the switch it takes one minute before the system resets the vents - a sound you probably wouldn't hear anyway - and TEN minutes before the fan turns on. And that makes sense -- no point running the fans while the cooled a/c air inside teh vehicle is still lower than the outside temp.
Grahamy, I get where you're headed, but have waited from a few minutes (more than 10) to several hours on many different occasions. My prime example is when I left the car out in full sun in 84°, put an indoor/outdoor thermometer in the floor on the front seat (out of direct sunlight), with the venting turned on and after 2 hours the outside temp read 84° and the inside temp read 111°. There was no mistake about it, the inside was HOT.
Was the fan operating? I've seen highly elevated temps on surfaces in sunlight as well. However, air temperature (out of the sun) is far cooler. Surface temp on the floor is no higher than 10˚F hotter than ambient.