The relay can not be inspected visually but there are ways to test them.
Slk roof switch not working.
They often seize up give the rod a bit of a twist and then close the boot.
One trick that you can try is to locate an identical relay in the fuse box keep note which system it serves and swap it with the convertible top relay.
Check the convertible top relay as well.
Slow blinking red light.
Replace the convertible top relay if necessary pn 0025421319.
If not the switch or wiring between the switch and relay could be the problem.
You can also bridge the top relay for a couple of seconds to see if the hydraulic pump start to run.
Next check the micro switch where the divider locks.
When putting switch in close position answered by a verified mercedes mechanic.
There s loads it could be but make sure you have the blind pulled out in the boot and have a look at the rod that goes from the boot push key hole down to the latch.
Swap it with a known working relay that is identical.
Roof will not open after dead battery.