Boot soft close failed

[Moulari]

Hello
Regarding a Mercedes Sl 350 2006
My boot soft close suddenly stop working few days ago
I checked the 20A fuse and is not burned
It worked when I insert the fuse back for 5-6 times and then fails again
Central locking is working fine when lock or unlock the car
Lumber support never worked since I bought the car( 10 months ago )
The fuel filler cap is been disconnected and sealed from the previous owner (because the cap doesn’t stay closed need to close it manually from inside the boot, checked if is leaking from there but is sealed
I checked the boot lock mechanism if it’s leaking with some soapy water but no lack I sealed the small ball bearing of the mechanism with some glue just in case but still the soft close fails after a few tries
Any idea what is the cause?
I thought it was the PSE but the central locking is working
Thanks
Aris

 

[Botus]

an air leak that got worse? if it comes to life poking the fuse, sounds like that resets and then it dies again

not all car doors close using the PSE for example w221 doesn't, but the 220 did

 

[LostKiwi]

Typical symptom of a leak to the boot.

 

[star]

If the boot actuator isn’t leaking, it’ll be the central locking pump.