Hey I know that a lot of older Mercedes often have vacuum issues such as the door locks. Well, mine have worked off and on for a while, but my dad, being the awesome mechanic that he is, figured out that on my car if you lock the trunk, all of the door locks always function! How strange is that. So locking the trunk and leaving it so the key hole is not vertical but horizontal makes the door locks function normally. Strange crazy old German electronics! Try it and see what happens. I'm curious to know what others experience.

 

mine dont work at never did from day i bought any sugestion on where i should start and also how should i look for a leak thanks bunch

 

I would check the fuse first. That's what was wrong with mine. Also fixed the rear dome light...

Other than that I dunno. I would check the vacuum pump. If it's never worked. It's under the rear seat.