Astra's Multiple Electrical Faults, Battery or Something Worse?

Hey there! I have some experience working on cars and had a similar issue with my 2011 Vauxhall Insignia 1.8. The symptoms were almost identical, weird electrical issues, dim lights, and starting problems. Took it to my regular workshop last year, and they found a faulty cable connection to the control unit that was messing with the BUS system. Cost me around 260€ to fix, but it sorted everything out. Haven't had any problems since. Before I share more specific details about my experience, could you tell me if you've checked the battery's condition and if you're getting any specific error codes? Also, how long has this been happening? I went through quite a headache with this, so I might be able to help point you in the right direction.

Thanks for sharing your experience! My mileage is at 216,339 km and I've had this issue for about a week now. Haven't checked the battery properly yet, but I'm planning to get it tested tomorrow. The error code I'm getting is P0685, which seems to be related to the power supply control circuit. The weird thing is that sometimes it starts perfectly fine, and other times it really struggles. Do you remember if your issue was intermittent like this too?

Hey again! Yeah, I totally remember having those exact same intermittent issues with my Insignia. The way your car's behaving sounds super familiar, mine would sometimes start up perfectly fine, and then the next time it would struggle like crazy. Really frustrating stuff! That P0685 code is actually exactly what I got too, which makes sense since it's related to the power supply control circuit. In my case, the intermittent nature of the problem was because of a corroded connection that would sometimes make contact and sometimes not. When the connection was good, everything worked fine, but when it wasn't... well, you know how it goes. I'd definitely get that battery tested like you're planning to, but based on my experience, I'd bet you're dealing with a similar electrical connection issue. When my mechanic fixed that faulty cable connection to the control unit, it solved all those unusual electrical gremlins. Since you've got similar mileage to what my car had when this happened (mine was around 205,000 km), it's probably worth having them check all the main power connections while they're at it. Better to catch any other potential issues before they cause problems. Keep me posted on what you find out with the battery test, really curious to know if you're dealing with the same thing I did!

Thanks so much for the detailed response! It's really reassuring to hear someone else had the exact same symptoms and got it sorted. The intermittent nature of your problem matching mine definitely makes me think you're right about the connection issue. I'll get the battery tested tomorrow as planned, but I'll also ask my mechanic to specifically check those power connections you mentioned. Really appreciate you sharing all this info, it's given me a much better idea of what to look for. I'll probably book it in for next week and make sure they check all those points you mentioned. The cost seems reasonable too if it fixes everything. Thanks again for taking the time to help out, I'll update the thread once I know what the actual problem was!