It's been a while since I've been to DIY section. I thought we should have a dedicated thread to the following issue: Intermittent seat adjustment problem. I have replied to the thread on Benzworld
but thought I'd share my experience with SLKWorld members
I performed this repair a while ago and still have some pics.
The problem I came up with is that sometimes my both seats wouldn't adjust out of a sudden. I was cleaning the car and has folded both of my seats, opened the roof and was busy busy cleaning =) Then, when I was done I had to go and pick up my wife. And guess what... My seats would not adjust!!! They stayed in this awkward position where I wasn't even able to drive... That was awful! After some jiggling wiggling - turning ignition on/off, starting the car, kicking the tires, cleaning the headlights..
I just gave up and went home. Couple minutes later I came up to the car and... Both seats started working!!! I immediately adjusted them in the comfortable position and the same evening went to research the problem!
The problem is that over the time the contacts on the seat relay get "cracked" and it causes intermittent failure.
There are two solutions:
1. Buy a new seat relay $35-50. Part #: A 002 542 22 19
2. Solder cracked connections! (Really cheap and easy)!
a. Solder iron
c. Solder cleaner (optional). I used wet sponge.
d. Patience =)
So, to fix that you first need to disassemble the lower dashboard.
For the instructions, please follow these directions all the way to step 9.
And you will be able to get to the seat relay:
Simply pull it out:
Now you need to open it. Use a flat-head screwdriver or any other similar tool. Be careful to take a note how the contact board is located so you don't damage when sticking your screwdriver in!!!
After you managed to disassemble it you have the following:
I pointed to the cracked contacts on the picture. Mine had about 5-7 of them!!!!! I think it happened due to extensive heat here in Texas.
Here's another picture so you can see it:
Inspect your relay for cracked contacts! It may contain 1 or many!
Now, all you have to do is solder it! Really easy! I'm not a professional solder-man and this was my first time too =)
Get a solder iron. (You can borrow one from your friend or buy one at Radioshack). Then get some solder. DO NOT buy cheap one in a dollar store! Get one from Radioshack. Will cost you $3-5.
Then just get to work! Here are some of the tutorials which helped me!
Make sure all cracks are covered with solder!
After you're done assemble the relay and plug it back in. Test if your seats work!
As I've said I did mine couple months ago and it works fine!
P.S. saved money was spent on LED bulbs =)