Thought I would compile a complete list of LEDs I bought to replace all of the factory incandescent bulbs (except high beams, I don’t use em) on my 2012 GLK. I have purchase links included as well. These lights have been installed for two weeks now and I have had no errors as a result of the bulb swaps. It took me a while to find all the different sizes in canbus-friendly LEDs, so maybe this list will help some of you trying to do the same. I will say they’re all an improvement over stock, but the low beam HL and fogs are a must!! The factory bulbs are dull and yellow, not a good look for a Benz imo. Anyway, here’s the info:


Headlights low beam


Fog lights

Rear park/brake lights (red, not pink)
**EDIT: these did throw a warning on the dash, even though they’re the right size and wattage. I haven’t tried any others yet




Rear turn indicators (thinking of swapping these for same brand as front because these are not as bright)


Front turn indicators


Marker lights (link is good for yellow/red/white, I bought all of them and they look great)
**EDIT: I removed the front and rear side markers, only keeping the white standing lamps in the front. The yellow and red threw warnings on the dash, but the white ones in the front have not caused any problems. Also I ended up buying another pair of white and using them for the license plate lights.


Also bought a 10pk of T10 for the license plate lights and assorted interior lights. I like these because they have a clear rubberized plastic coating around the led boards so they’re pretty much waterproof/dustproof.
**EDIT: these lights suck, no other way to put it… The light output isn’t consistent and they don’t sit right in the bulb sockets. I used a set of the white marker lights instead, link above, they work great

 

This post is awesome! I just picked up a mint 2012 GLK 350 and wanted to do this as well. Any "gotchas" I should look out for?

 

There's a couple things to watch out for at the front:
I removed the front wheels to get to the headlights and fog lights. After reading how difficult it is going thru the top (and realizing I cannot change the size of my hands...) I figured the 5 minutes it takes to lift it up was worth it, and it totally was! With the wheels off, took like 10 minutes to do both sides, no broken tabs.
The park lights below the high beams took a bit of doing, too. I removed the high beam bulb to get to them, not certain if this is absolutely necessary but it gave me all the room I needed.
But that's pretty much it, no real surprises, just figuring out what you have to move.

 

Thanks! Quick question. I was going to go ahead and order some for low beams and brake lights. Amazon says these do not fit the 2012 GLK 350. Did you have issues with these?

 

UPDATE: I got an error on the dash last night for the left tail and brake lights only (when LEDs are on the right side as well…) This is after they have been installed on the car for close to three weeks. This is the first and only error….

So to answer your question, the bulb size is correct for the brake lights, they fit, but don’t buy those.

Honestly, because the housing lens is red, the brake lights make the least difference being LED vs the factory incandescent. I’m going to swap back to the OEM brake bulbs for a few days to see if any other errors come up.

Buuuuuut, zero issues with the headlights. They fit perfect, they’re plug and play, there’s no flickering and they’re clear, crisp and bright as heck. Highly recommend it!

 

Duval, I wanted to Thank You for the GLK Low Beam LED swap info! I have a 2014 and the Halogen lamps, as we know, are sub par. I did not want to join the HID Blind the other guy club but the LEDs were lagging behind in the plug and play department, until recently apparently... The Farhen product you linked to works Beautifully! Relatively easy to install(remove the wheel well liners...) and so far Total plug and play. I do like to have high beams available, the factory H-15's are weak yellowy accents now. So that's next on the hit list. Thanks again!

 

Glad they work out for you, happy to help!

Also want to provide an update on the other LEDs. Since removing the brake light bulbs a couple weeks ago I have had no other errors come up, so all the other bulbs are verified to be plug and play and error-free.

 

There are a number of LED H15 replacement bulbs that claim to work with the GLK series. Anyone tried any of them?

 

I used the "Red Wolf" brand off Amazon. They were a ***** to install, particularly the drivers side, but that may be down to my hands, etc. However, they are total plug and play, match the new "Fahren" brand LED low beams nicely and have revolutionized the night driving experience. I recently moved to a mountainous, unlit twisty road area with Lots of deer, elk, fox etc. so I needed to upgrade from the halogens, these have been outstanding.