Technical yellow padlock symbol on the dashboard and the engine doesn't start

[elbahey]

the engine doesn't start with the sound of marsh ( starter ) and i get this lock symbol in the first photo
yesterday the maintenance technician opened the connector in the second photo and cleaned it by clothes, it worked !
today i get the same issue and the engine won't start again >

i had tried to open the connector but i failed to open it <]]

any recommendations
thanks in advance

 

[Reg 65]

There will be some sort of catch holding the 2 parts of the connector together - probably the red piece at the top in your photo?
You have to squeeze the catch to release it. They can get corroded and stuck together, but since it was separated recently it should come apart ok.

 

[bugsymike]

Pull back the yellow locking bit then the red part should slide back to unlock.
If you look up the red bit at the end away from your hand you should see through the holes the end of the yellow bit, sometimes it is necessary to push a tool or two screwdrivers up the holes to retract the yellow bit, this will then allow the red bit to release and slide back unlocking the wiring plug.