Defender's Mystery: Flickering Lights & Battery Blues

Hey there! I've got some experience with cars (let's say medium level DIY-er). Had a similar issue with my 2006 Discovery diesel last year. Those Land Rover electrical gremlins can be tricky! My symptoms were pretty much identical, weak starts and flickering lights. Turned out the battery was completely shot, and it was affecting the whole electrical system. Took it to my trusted mechanic, and after running diagnostics, they confirmed it wasn't the alternator (which was my initial worry). The fix was straightforward, new battery installation and a thorough check of the charging system. Cost me around 290 Euro all in, but it's been running perfectly since. Before jumping to conclusions though, what's the battery's age in your Defender? Have you noticed any other electrical issues? Sometimes these symptoms can point to different problems depending on the specific model and year. Feel free to share more details, and I'll try to help further! Cheers!

Thanks for the detailed response! Yeah, mine's done 133777 KM and had its last service about 6 months ago. The battery's actually fairly new, replaced it last winter, which is what's making me scratch my head about this. You mentioning the alternator got me thinking though. I did hear a slight whining noise recently, but figured it was just typical Defender character! These older Landies can be proper puzzles sometimes with their electrical quirks. Might have to bite the bullet and get it properly checked. Did your mechanic use any specific diagnostic tools for the charging system? Just wondering what I should expect when I take it in. Cheers for the help!

Hey again! Ah, now that's interesting about the whining noise, that sounds really familiar! When my Disco started doing that, I initially brushed it off too (you know how these old Land Rovers love to make "character" noises). Since we're talking similar vintage vehicles here, let me share what happened next with mine. Even though my battery was shot in my case, that whining noise you mentioned rings some serious bells. When I took mine in, my mechanic used a multimeter to check the charging voltage, turns out my alternator was on its way out despite the initial diagnostics. The bearing was going, hence the whine. They used this fancy diagnostic tool (can't remember the exact name, but it was some pro-grade equipment) that monitored the electrical system while running. Showed all sorts of voltage fluctuations that weren't obvious otherwise. Quick tip from my experience, get them to check the voltage regulator too. These old diesels can be sensitive to that, and it's often overlooked. My repair bill ended up being more than just the battery replacement I mentioned before, but it sorted all the electrical gremlins. Keep us posted on what you find out! These old Landies might drive us crazy sometimes, but they're worth the hassle, aren't they?

Hi everyone, thanks so much for all the helpful info! Just wanted to update you all, finally got the Defender checked out today. You were spot on about that whining noise! Turns out my alternator was indeed the culprit. The bearing was failing, and the voltage regulator was also playing up, causing those flickering lights and weak starts. The mechanic used their diagnostic equipment and showed me the irregular voltage patterns. Pretty fascinating stuff actually! They're ordering the parts now, and should have it sorted by next week. Really appreciate everyone's advice, especially about checking both the alternator and voltage regulator. Saved me from potentially just replacing parts! These old Defenders might be temperamental, but there's something special about keeping them running right. Will let you know how it goes after the repair. Thanks again for all the help! Cheers!