Dear professional engineers I have a problems and i need your help I do not know what is the reasons,
My lovely car is W124 E320 1994
1 - i hear a fuel pump wizzing in large sound inside the car its nervous me so much .
2- down the back seat (rear seat of passengers )there is a computer they have 4 connection cables one of them connection used for centerlock and i find the next one is disconnected when i try to connect it the sunroof is open by itself and i hear the motor works continually

3- the head restraints of rear seats is not work i trying to inspect the air connection and find all connected then trying to inspect the electric connection also every connection is connected

4- some time after i drive the car for while then i stopped in parking to get some stuff from the market when i back to turning the car it's won't and no cranking i trying more and more and there is no response and trying to disconnect the battery for while then try again it's not working so that i leave the car for one hour then back to it when i trying to crank it's work normally
Thank you so much professional