Infiniti EX Climate Control Woes: Solar Sensor Suspect?

Hey there! I've had some experience with similar HVAC issues (some car repair experience here). Actually, my 2009 Infiniti FX35 had almost the exact same problem last summer. Like you, the whole climate control system was acting weird. Turned out it was a faulty wiring harness that was causing all sorts of crazy behavior with the blower and temperature control. Took it to my regular workshop, and they diagnosed it pretty quickly. The repair took about 3 hours, and I paid around 155€ for the whole thing, including labor. But before I share more specific details could you tell me if you're getting any specific error codes? Also, does your blower work at all, or is it completely dead? This would help me give you more relevant advice based on my experience.

Thanks for sharing your experience! My mileage is at 229,061 KM, and yeah, the blower is still working but super inconsistent sometimes it's fine, other times it barely pushes any air. Haven't pulled any error codes yet, but that's probably my next step. The warning light just started showing up last week after my regular service. I'm hoping it's just a wiring issue like yours was, sounds way better than having to replace the whole AC system! Do you remember if your car made any weird noises before you got it fixed?

Oh yeah, I totally get what you're describing! My FX35 had very similar symptoms when it was around 235,000 KM. And yes, actually before I got it fixed, there was this annoying rattling noise coming from behind the dashboard, especially when I would change the fan speed. Looking back at my situation, I should mention that the first mechanic I went to actually thought it was the solar sensor too (like you initially suspected), but that wasn't it at all. The wiring harness was basically corroded and had some loose connections, which explained the inconsistent blower behavior. Since you mentioned it started after your regular service, I'd definitely suggest checking if something got disconnected during the service. In my case, I noticed the problems got worse in humid weather was that something you experienced too? One thing I learned from my experience don't wait too long to get it checked out. I initially tried to just "live with it" for a few weeks, but it only got worse and started affecting other electrical components. Better to catch these things early! By the way, have you noticed if the problem is worse at certain times of day? In my case, it was particularly bad during morning starts.

Thanks so much for all these details! And yes, actually now that you mention it, the rattling noise sounds exactly like what I'm experiencing, especially during morning starts! It's definitely worse when it's humid too, which makes sense with the wiring harness theory. You've honestly made me feel a lot better about this whole situation. I was really worried it might be something major, but hearing that yours was just a wiring issue gives me hope. I'll definitely get it checked out this week instead of putting it off. The fact that your repair only took 3 hours and wasn't super expensive is a huge relief. I'm going to call my mechanic tomorrow and specifically mention the wiring harness possibility. Really appreciate you taking the time to share your experience it's been super helpful!