So recently I had trouble with the alarm coming on randomly and the locks not working at all and then they would work fine a couple days later. I pulled the styrofoam up in the trunk and found the pump sitting in a couple inches of water. I pulled the plugs on both sides of the trunk and drained all the water. I removed the pump from the car to let it dry. My question now is how do u test the thing without just throwing it back in the car and waiting for more alarm problems to happen? Has anyone tried to repair it own their own? Also, do the c320, slk320, and slk230 all share the same pump as the crossfire cause I may go to a pick and pay to avoid paying $500 for a new one?

 

I can tell you that they do not, as I ordered one from eBay at a very low price just to see, and found that although the electrical connectors seem to be the same, the vacuum hoses are not.
I tried it anyway, it didn't work, possibly because it was bad to start with, I don't know.

 

Well that kinda blows......so much for cheap alternatives.

 

My info says that the SLK230, 320 and 32 share the same pump as the Crossfire. Part number 170 800 08 48. Check the eBay listings under that number.

 

That explains it then. The one I have is a 210 800 10 48.
Back when I ordered it from eBay the listing said it would fit a slk320, should have known better with a part number starting with 210 .......

What the heck, only gave $35 for it.

 

Thanks, I guess I'll check eBay then.

 

Also, are the interior lights controlled by the central locking pump because I was having problems with the light staying on unless I turned it to the off position and then a couple days later it wouldn't work unless I turned it on by pushing it in?

 

The interior lights are timed out by the locking pump.

 

So I ended up buying a used pump on eBay. Installed it this evening. Everything is working properly now. I pulled the drain plugs in the frame on both sides and put the new pump in a trash bag so when water does find its way back in the trunk it should not be a problem. Now I'm just waiting on the Mercedes panel retaining clips to arrive that I ordered from amazon. I broke a couple off trying to remove everything and couldn't find the Mercedes style ones in any automotive stores.

 

Late to the party - but there's a very long 17 page thread over at the R170 forum. Other may end up here and go there.

I personally spent a lot of time with these about 6 years ago....on my SLK230...same pump as my SLK32 (=crossfire SRT6 in mercedes clothing - or the other way 'round)
I ended up buying a new pump back then. Then when I got the SLK32, I actually took my new 1999 SLK230 pump out and put it in my SLK32 and vice versa.

This 17 pager post indicates the interior light timer is tied in with the PSE (Pneumatic...something something...)
here

Lots of info for others...but glad to hear you got it fixed.

b22b