baobay

Hello all,
Trying to locate the negative terminal for the 12V battery in 24 GLC 43 AMG so I can disconnect it in order to do the Distronic Plus Retrofit.
I can see the 48 V battery and the 12 V positive terminal once I remove the cabin filter under the hood on the passenger side. I cannot seem to locate the 12v negative terminal. Any help would be appreciated. Thanks.

DESAL

don’t know if this helps. But on my 23 300 SUV the 12v is located in the engine compartment. Top left hand side.

baobay

Thanks for the reply. Yes, I removed the big plastic cover then the cabin air filter underneath to expose the battery. There is no 12V battery there. Only 48 Volt.

streborx

The 12V battery is likely not in the engine compartment. The 12V terminal under the red cover is for charging and jump starting. Search the forum for 12V battery location -- someone might have posted this info.

BTW, the 12V negative terminal for charging/jumping is usually just a large steel lug mounted somewhere closeby the red cover, and is mounted directly to the vehicle's chassis structure.

baobay

Im not looking for the ground terminal for charging/jumpstarting. Im Looking for the negative terminal which I can disconnect since it’s recommended to do so when installing the hardware for the retrofit. I have searched the forum and online but can’t seem to find the location. I’m starting to think there isn’t a 12 V battery!
it may be a combined 48/12v battery. I’m fairly certain but not 100%.

streborx

This says it's under the cabin filter.
https://www.autotrader.co.za/cars/ne...lc-coupe/14270

baobay

Yup. I removed the cabin filter and mine looks nothing like this. I did reference the link you posted before hand as well. Under the air filter is the 48 volt battery.

baobay

I wonder if this could be the negative 12V terminal...

streborx

I'd check under the floor in your boot area, and then under the rear seat next.

baobay

No Luck. In my wife’s GLS it’s under the driver’s seat, under the vent cover. No luck yet in finding it in the GLC…anywhere.

Eric Baum

Your 12volt battery should be located under the rear compartment cover. Mine is next to the spare tire

baobay

BINGO!! Thank you very much. I don’t have a spare. I peeled off the padding and there it was. There’s actually a very small access opening to what is the negative terminal of the 12v battery. This gives access without the need to peel off the covering.