Why did the instrument cluster just stop working?

ROBERTRISSMAN23

MEMBER
2006 MERCEDES BENZ S430
4.3L
V8
2WD
AUTOMATIC
91,700 MILES

I was driving and my instrument cluster just stopped working. Didn't light up, all of the gauges worked except my speedometer which was stuck at 40 mph, I just couldn't see them. So, I checked the fuse box and sure enough the fuse for the cluster was blown. So, I replaced that and now the fuse is brand new, and the speedometer works again, so all the gauges are working, but they still won't light up and I can't see them at night. Also, the check engine light is on now, but it happened when I changed the fuse so I'm hoping it's got to be because the clusters having issues.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

Yep, the fact that the fuse was blown means the cluster is having internal issues. But I can also tell you it might be the front SAM control unit as well. Here is the cluster wiring diagrams so you can see how the system works and there are other fuses that must be checked as well, which are listed in the wiring diagrams (red arrow). Also, I have included how to remove the cluster for inspection.

https://www.2carpros.com/articles/how-to-check-a-car-fuse

When the cluster is removed see if you can smell or see anything that is burnt? Check out the images (below). Please upload pictures or videos in your response of any problems so we can see what to help you with.

Images (Click to make bigger)