Flickering Headlights & Weak Starts: Vectra Battery Woes

I had a similar issue with my '07 Vauxhall Astra (2.0L petrol) last year. The battery temperature sensor went bad and caused exactly these symptoms, dimming lights, weak starts, and general electrical weirdness. Took it to my regular garage and they diagnosed it pretty quickly. The faulty sensor was causing incorrect voltage readings, which meant the alternator wasn't charging the battery properly. The sensor itself sits near the battery and monitors temperature to adjust charging rates. The fix wasn't too complex, they replaced the sensor and had to recalibrate the charging system. While they were at it, they tested the alternator and battery, both turned out fine. Car's been running great since then with no electrical issues. It's not a super serious problem if caught early, but it can damage your battery or alternator if left too long. My mechanic said he sees this fairly often on Vauxhalls from that era. Hope this helps with your Vectra!

Thanks for sharing that! My issue sounds exactly like what you described. Really helpful to know about the sensor causing those charging problems. Did you remember roughly how much the whole job set you back? Also, has everything been running smoothly since, or have you noticed any other electrical quirks pop up? Just want to know what I might be in for with my Vectra.

Hey again! Yeah, I can definitely confirm everything's been running perfectly since I got it fixed, no more electrical gremlins at all! The repair cost me 315€ total, which covered the new battery temperature sensor and the recalibration work. Looking back, it was worth every penny because the car's been running like a charm since then. Tell you what, when they fixed the sensor, it was like night and day difference. No more dimming headlights, the engine starts first time every time, and all those weird electrical issues completely disappeared. It's been about a year now, and I haven't had a single problem since. If your symptoms are similar to what I had (and it really sounds like they are), I'd say go for it. These Vauxhalls are pretty solid cars once you sort out these little sensor issues. Just make sure you get it done sooner rather than later to avoid any damage to your battery or alternator. Good luck with the fix! Let us know how it goes!

Just wanted to update everyone, got my Vectra sorted last week! Took it to Johnson's Auto on Mill Street after getting some recommendations. You were spot on about the battery temp sensor being the culprit. The mechanic I found was great, really knew his stuff about Vauxhalls. The whole thing cost me about 330€, pretty close to what you paid. The best part? All those electrical problems are completely gone now. Headlights are bright as they should be, and the car starts up perfectly every time. It's amazing what a difference fixing one small sensor made! They did warn me about getting it done just in time, apparently, my battery was starting to show signs of stress from the irregular charging. Really glad I didn't wait any longer. The mechanic was super thorough, did all the testing and recalibration you mentioned. Thanks again for the advice everyone, saved me from a lot more expensive repairs down the line. If anyone else runs into similar issues with their Vauxhall, I definitely recommend getting that sensor checked out first!