Removed my bumper to install the PLM XL heat exchanger in my CLS55 and noticed these two yellow and brown wires with connectors and a hose that’s plugged by a bolt. I bought this car two and a half months ago so I have limited knowledge when it comes to the wiring. Any input will be appreciated

Those look like the horn wires.

Edit to add: the hose might be for your headlight washer fluid.

The headlight washer hose explains why it isn't working, although I don't use it. My horn on the other hand works fine though. Are there multiple horn sirens?

On an E55, the wires you pictured are the horn wires.

Check and see whats plugged into the horn presently. Also if you have an extra horn, hook it up to those wires and see if it works.