1995 S420 Power lock

Hello All, I"m a new owner of 95 S420. the door assist is working fine for all doors except the trunk...actually you have to slam the trunk down for it to close.
1-the power lock funtion does not work.
2-all the doors have to locked manually.
3-the drivers side door must be closed from the inside.
4-both the remote and receiver seem to be funtional only the lock/unlock mechanism does not engage.
I'm hoping I don'y have to replace the vacuum since it is so expensive...what else could it be besides the vacuum?

thank you very much.