Thanks to all who contribute to this great site.

Spent about 1 hour and NO MORE WONDERING IF THE SEAT IS GOING TO WORK. I had more time looking for the soldering iron than repairing the relay. I'm sure it not as good looking as some of the repairs but it works.

I know exactly how you feel! Worst case scenario, you just buy a new
MB relay for $30... Definitely much, much cheaper than having a
MB dealer fix it for you!

If I were a Mercedes dealer, I probably wouldn't like this forum very much.

No one has regaled this fix in 2009 so I want to say thanks, I saved big bucks with this simple fix.

nearly 10 months after I replaced this power seat relay,
it is still working perfectly. come to think of it, I haven't
even thought about it in nearly 10 month.(which is a
good thing)

I think it'll be obvious once I buy a replacement relay. But, how do I remove the existing relay? Does it pull straight out of the base? And then the wired connector pulls out of the relay itself? The relay itself felt loose. But I was afraid to try too much without knowing whether that was the proper way to remove it.

This will be a HUGE improvement to my 2000 C280. Right now I can adjust the seats before I get in the car. They quit working once I shut the door. but they work again as soon as I crank the car, but only for a few minutes. Then they don't work any more until the car has been turned off for a while. Makes it very tough for my wife and me to swap the car out. She's 4'10" (i.e., short!).

Thanks!
-Harry

I simply pulled the relay straight up and it came off without any problems.

As with any type of electrical repairs, please disconnect the car's battery before proceeding.

Yes, this is very true. There is no "better" solder necessarily, as different applications call for different metallurgies.

The thing about lead-free solder that most people don't realize, and what leads to a lot of its bad rap, is the fact that it doesn't produce nice shiny solder joints like a good lead solder will.

With lead solder, the color of the solder joint is a very good indicator of how well the electrical and mechanical properties of the joint are. Lead-free solder can make a perfectly good solder joint that looks dull and "cold", and it takes a long time to mentally adjust yourself to that, leave the joint alone, and go on to the next one. People used to lead solder will tend remove the old joint and re-solder it over and over thinking that they are getting a "cold joint" or a contaminated joint. This leads to frustration and reports that the non-lead solder isn't as good.

One thing's for sure, it definately requires more heat. I try to avoid it when working on heat sensitive components for that reason.

There are MANY different lead-free solders on the market. I have most recently used the green labeled version by Kester, which uses antimony instead of lead. Not exactly a less toxic metal in my personal opinion, though the amount of antimony is low and just added to increase strength.

I agree that through-plated holes in the PCB would have likely prevented this issue. Just remember - failure in less than 5 years = money loss. Failure after that period means money gain. That calculus finds its way into manufacturing decisions, you can bet on it.

__________________
-tp


1990 300SE "Corinne"- 145k daily driver - street modified differential - PARTING OUT OR SELLING SOON - PORTLAND OR. AREA - PM ME FOR DETAILS
1988 560SEL "Gunther"- 190K passes anything except a gas station
1997 S420 - 265k just bought it with a rebuilt trans. Lovely condition

I don't think that is necessary in this case. IMHO.

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

Ditto on my '98.
Intermittent seat operation.
This was a 20 minute fix to remove and re-solder the relay connections!!
Thanks!!!

My wife has a 1998 C230. The drivers seat works forward & backwards, but the seat back will not tip forwards or backwards. Before I start testing things I know nothing about, has anyone had (& fixed) this same problem?

Thankful for any info.....

I never heard of it on this car (yet...). I had a similar problem with the drivers headrest not working. In that case it was another case of failed solder joint on single-sided circuit board. But this time it was right at the motor for the headrest which is in the seat back. I am not sure of the location of the motor for the seat back, but could be in the set back also, otherwise it would be under the seat. The back trim panel of the seat is pretty easy to remove. There are two torx screws on the bottom. If you search for my head rest thread then I tell the size of the torx there. You would then put a volt meter on the motor connections or wire to it and see how far the voltage is getting.

__________________
1998 C230 330,000 miles (currently dead of second failed EIS, yours will fail too, turning you into the dealer's personal human cash machine)
1988 F150 144,000 miles (leaks all the colors of the rainbow)
Previous stars: 1981 Brava 210,000 miles, 1978 128 150,000 miles, 1977 B200 Van 175,000 miles, 1972 Vega (great, if rusty, car), 1972 Celica, 1986.5 Supra

What about the same problem with the front windows?? Another relay perhaps?

Is it both driver and passenger windows?
or an issue in the center console.

What year is the car? and does your remote have the windows-down/up feature? and will the remote move the windows?

1998 C280. Remote doesn't have window controls. It's just the driver window. Other issues are the seats work intermitentantly (that's how I got onto this post) and driver side electric meter isn't working. This is a car I am looking at buying for my son. I am trying to see if these things can be fixed reasably cheap or if I should not buy. The owner says windows just randomly start/stop working. Thanks for any help.

I meant electric mirror doesn't work.