The last time I used the car about a month ago it started fine but now it won’t start at all. I sprayed starting fluid in the air intake and it ran for a few seconds so I figure the ignition system is fine plus I also pulled and cleaned all the plugs. I hooked up a fuel pressure gauge to the fuel rail and it shows strong pressure so the fuel pump is good. Lastly I plugged a noid light into one of the injector connectors and cranked the engine and it didn’t flash indicating the injectors aren’t getting a signal to open. Where should I go next? Is there a fuse that controls the injectors that may have blown and if so where is the fuse box?

OVP relay

I don't think it has a physical relay like the older cars. If it does, where is it?

What is the chassis # ???

Wdb1400281a239252

I don't have info for gray market, but I assume it is a 104 -2.8, S class.
[ like the S320].
So, it may not have OVP.. Just look behind the panel, behnd the battery. if it has one . it will be there w/fuse on top.
if it does not, spin all your fuses for a better contact before checking crank sensor.