stefanfuchs9

GLK Reduced Power and Flickering Lights

I've got a 2009 Mercedes GLK with a gasoline engine. The engine power seems reduced, and there's a warning light on the speedometer. It's also started poorly a couple of times. I've noticed the lights are weak and sometimes flicker. The error memory has something stored, but I don't have the exact code right now. My suspicion is a faulty generator, and from what I've seen online, an alternator replacement might be needed. I am looking at 960€ for the repair. Could this be related to a battery low issue or a voltage drop somewhere in the charging system?

4 comment(s)

I had a similar alternator issue with my GLK. Reduced power and flickering lights sound familiar. A voltage drop can definitely cause those symptoms. Have you checked the battery terminals for corrosion? Sometimes a bad connection can mimic alternator problems. The alternator is basically what keeps your battery charged while the engine is running. If it's not producing enough power, your battery slowly drains, leading to all sorts of electrical weirdness. By the way, the charging system is responsible for keeping the battery charged by using the alternator.

Thanks, that’s helpful. I haven't checked the battery terminals myself yet, but I can definitely take a look. Was your issue also intermittent at first? And did you eventually need a complete alternator replacement, or was it something else causing the charging system problem?

Yes, my issue was intermittent to begin with. It started with occasional flickering lights and then progressed to reduced power. I eventually needed a complete alternator replacement. Based on your symptoms and the error stored in the memory, it sounds like you are heading in the same direction. I'd suggest having a workshop confirm the generator is defective. It is better to let professionals handle the alternator issue and confirm the repair cost.

Thanks for sharing your experience. That's really useful to know. I took it to a mechanic, and they confirmed it was indeed the alternator. Getting the alternator replacement done now. Appreciate the help!

Join the discussion now: