Faulty Insignia HVAC: Solar Sensor Mystery & Mechanic Need

Hey there, I had very similar issues with my 2016 Vauxhall Astra (1.4L petrol). The symptoms you're describing sound exactly like what I experienced last month. Initially thought it was just the solar sensor too, but turned out to be a faulty wiring harness in the HVAC system. Took it to my regular garage and they found several worn-out connections in the main harness that controls both the fan and temperature settings. The warning light was definitely related to this. They had to replace the entire wiring harness assembly as it was pretty deteriorated. It was a serious job that took them about a day and a half to complete, mainly because they had to remove quite a bit of the dashboard to access everything properly. But since the fix, everything's been working perfectly, stable temperature, normal fan operation, and no more warning lights. Given your mileage, I'd definitely get the wiring checked out. These issues usually don't fix themselves and can actually get worse over time. Hope this helps!

Hi! Thanks for sharing your experience, sounds like you hit the nail on the head with that diagnosis. The wiring harness seems like the likely culprit in my case too. Just wondering, do you remember roughly how much the whole repair set you back? Also, has everything stayed sorted since the fix, or have you noticed any other quirks popping up? Cheers!

Hey again! Glad I could help! After seeing your message, I wanted to let you know that everything's been working perfectly since I got it fixed. The repair totally solved both the wiring harness problem and the solar sensor fault, they spotted that issue while they were in there too. The whole thing set me back 155€, which honestly wasn't as bad as I was expecting for such a detailed job. Haven't had a single problem since then, the temperature stays exactly where I set it, the fan behaves normally, and that annoying warning light is gone for good. It's been so nice having a properly working HVAC system again, especially now that the weather's changing! If you decide to get it looked at, just make sure they check both the wiring and the sensor. Sometimes these things are connected, as I found out. Let me know how it goes if you get it sorted! Take care!

Thanks! Really appreciate all your help. Just wanted to update you, I finally got the courage to take it to a mechanic yesterday. Turns out you were spot on! The wiring harness was the main issue, though they found the sensor was a bit wonky too. Cost me about 180€ for everything, including labor. The funny part was when I got there, the mechanic took one look at the dashboard and said "Ah, classic Insignia problem!" Made me feel better knowing it wasn't just me! They sorted it out in about 4 hours, and I've got to say, it's like having a new car. The AC's working perfectly now, no more unusual temperature swings, and that pesky warning light is finally gone. Thanks again for giving me the confidence to get it checked out. Sometimes you just need someone who's been there before to give you that little push! Cheers!