C32boi

I got a c32 Amg here that has a tail light issue the two top tail lights don’t come on at all and the bottom two tail lights come on and then when I press my break only one break light on driver left side comes on? I have check and replaced all fuses that had any minor issues I looked thru some PDFs of the fuse diagrams and the relays and still cannot find where the fuse is itself?!? Ive been trying to figure it out for 3 days with no luck...any help from a old school Benz head would be awesome.

Spooky55

That is (almost) normal behavior. The top lights are brakes only and the bottoms are tail lights.

There are no fuses - they are controlled directly from chips on the rear SAM (smart fuse box).

C32boi

so how do I get it to work?

Spooky55

Short answer - you don't.

Longer and more expensive answer, rear SAM repair or replacement ($$$). A few hundred to about a thousand, and usually involving a shop with STAR/DAS/Xentry, as the installed options need to be programmed in.

You might get lucky and find a good one at the wrecking yard, but it'd have to be the EXACT same part number and from a car with the EXACT same options as yours, but there are a LOT of wiring connectors going into it, so you'd have to also be VERY thorough about getting everything labeled and plugged back into the right places. Then it also has to not have the same issues with the light bulb driver chips...

I'm not sure why Mercedes went this route, but I guess they wanted everything monitored on the BUS. My previous C55 had the right front side marker light out. Drove me nuts (mainly because I want EVERYTHING to work properly on my car).

I recently grabbed a rear SAM at the wrecking yard to tear down/have as a spare. I will be dismantling it to do a little reverse engineering on it to see what chip drivers they use to see if I can repair the hardware myself, but this is not a project I'll be getting to for a while...