LateLife Crisis

Decided to fit electrical oil pressure gauge to my right hand drive clk430. After fitting sender unit to the access port above the serpentine idler pulley ran the wire (white in photos) in the plastic conduit along the fuel injectors and into the fuse box which is on the left hand side in my car (has the 38pin diagnostic socket). This is where the work really started. I removed the scuttle covers, the top scuttle moulding, the windscreen wiper assembly and then the bottom scuttle drain tray. The scuttle drain tray could only be removed after removing the weird location pin near the accelerator actuator and then removing 5 x 8mm bolts from the inside bottom of the fuse box. You need to move some wiring around and use a magnetic pick up tool to remove and put these back at the end of the job. This enables the whole fuse box to be lifted and move forward slightly taking care not to overstrain the wiring which goes through a plastic duct straight into the under dashboard area on the passenger side.
I pushed the single wire through with hardly any resistance and you'll need to remove the under dash panel to access the wire just above the carpet (sorry about the dark photo). Whilst doing this job I did a fair bit of cleaning and found the scuttle tray main drain (blue arrow) to be fully blocked with leaves and debris. Used a flexible piece of plastic and water to clear. Also replaced the perished sealing foam on the fresh air damper, see photo. Hope this is useful for someone.