Hello,

I drive 2012 C300 4Matic, and I have a engine light one because of Secondary Air Pump. I purchased this car recently, but by looking at the pump body, it looks like it was replaced recently by previous owner. So fist thing I did was to check the Fuse, and it was blown. I went out and purchased a new Fuse but after a few rides, the new fuse was also blown. Also, when I checked there were few drops of water in the hose, looked like condensation. What could be the reason for Fuse to go out ??

I researched about the Relay. I know it's location but I don't know how to check the relay to be sure if it's faulty.

So, what should be my next steps? Please help me fix this.

Thanks in advance.

 

You may need to replace the two check valves that are part of the secondary air system.

 

Can you show me a picture of them? I don't know how do they look like? Will that blow fuse ?