The relay can not be inspected visually but there are ways to test them.
Slk roof switch not working.
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.
Check the convertible top relay as well.
Roof will not open after dead battery.
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.
When putting switch in close position answered by a verified mercedes mechanic.
Next check the micro switch where the divider locks.
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.
Slow blinking red light.
If power is going to the relay but it isn t clicking either test or replace the relay pelican 002 542 74 19 m44.
Relays are affordable and having a spare is a good idea.
If the relay and the fuse are not the problems move to the next step.