MB 420SEL - Power Windows & Central Locking
 

I'm working on an ' 87 MB420SEL:
1) Having problems with the power windows. When the 'Child Protect Switch' on the console is turned on (child icon exposed) the fuse 'D' blows otherwise I can operate all windows from the console switches. However, the left rear door window switch does not work. I've opened the switch plug/socket and made certain the soldered connections are sound and not shorting. I think the switch is sound as best as I could test it with an Ohm meter. Where to look for the culprit?

2) The cetral locking system just does not work. When I trun on the key, I don't hear the pump operating. So, there is no power going to it. Where should I go to look for the problem? All fuses checked out. Looking forward for some advise.
Thank you.
Joe