I have used the search feature and have not found any info that can help my present situation.

Here is my Problem.

For about 2 years now My powers seats have been getting worse in my C280

first they would only work after the car was started and running for 10 minutes but would work normally when I openned the door.


Now sometimes they don't work for days at a time.

I beleive it is a power supply problem of some sort because they either work at the same time or they are stuck at the same time so it is not the switches.


Is there control module for the seats that might be going bad (if so can someone tell me the location of it in a W202 chassis.

Could it be a relay that needs replacing. It is very annoying when you want to move the seat for whatever reason but you can't.


Help a brother out.

Hi Smartkey, My wife has been telling me for the last few weeks that the power seats in her 98C230 are inoperative at times. Checked them twice & they were workng ?? Comes home from the grocery store yesterday ,seats not working. Grab my digital volt meter & checked across seat fuses on under hood fuse panel,all OK. Fuse panel cover panel says there are related fuses in trunk.Removed trunk floor trim ,all fuses OK .Don't know where the seat relay is located . I suspect an inter- mitent connection , see 2 relays under a black plastic under cover with 3 fasteners & remove panel. Wife is turning key on & off while I listen & feel for relay click. One relay is mounted vertical & the other horizontal.Checked the one left (horzontal),have 2 input BAT volt- age readings for power feed & coil feed & relay is clicking ,trigger circuit OK. Check output on 12 guage Pink/white- BINGO - NO OUTPUT Remove relay cover,check contact points for continuity with ohm meter & then under duty load for current flow.Both tests OK. Check solder connection to circuit board with a magnafying glass on the output pin. There was a small circle crack in the solder around the pin. Cleaned up the old solder & resoldered the connection & it's operating as designed. My Motto "Repairs though testing " ---- Ray

Ray,

That is pretty good for a first post!! I have high hopes for you. And since I have that exact problem (among many others) can you please confirm that the board you repaired was inside the relay? Or was it some other board?

Thanks,

Mike

__________________
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

Hi Mike,---- Yes ,it is the small circuit board inside the relay. Once you remove the relay cover by sliding 2 small screwdrivers along the 2 release tabs, the cover will pop off. Circuit board is attached at right angle to base containing the male pins. If you have the patients & soldering skills with a small soldering iron ,it's a piece of cake job,& will save you some bucks, you won't have to replace the relay. I have been an electronic technician for over 40 years , sorry to say not at a Mercedes Shop. Own 2 Benz only because I can tinker with them, now that I am retired. Let me know if you need more help. Ray

Hi Ray,

I have been an electronic tech for 17 years, so you have a few years on me!! Just fixed the GF's Sony last week. Anyway, this will be the second bad solder joint I have fixed in this car. First one was the headrest motor which I detailed in a previous post. I have to admit I found electrical problems in my Toyota also, but never bad solder joints. Don't want to talk about the FIAT......

You will find many interesting electrical problems presented on this site. But often the tribal knowledge goes farther than electrical knowledge in fixing them!

Mike

__________________
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

Hi Mike,----- When you remove your relay,you will see it is made in Austria , I think it is expensive to replace because of the components on the circuit. My opinion is the pretty looking shallow solder connection can't handle the current flow after many years of operation, plus heat,cold & vibration. I built up the solder wider & higher ( ^ ) to carry the amps. Time will tell ,but I think it will hold up. Ohms Law will determine if it can handle it. ---------- Ray

Bingo - Solder on Pin 2 (12 volt output) was crystalized and fractured. I cleaned out the old solder using a solder sucker and built up the solder as ray95e320se suggested. When doing the repair, be sure to use enough heat to prevent creating a cold solder joint.

1999 C280K 98,000 miles

I purchased a new seat/accessory relay for my car. The relay part# is 002-542-22-19 and my dealer charged $38.50.

The plastic panel in the trunk that covers the relay is removed by 3 plastic screws, they are not a pop-off style fastener

Nice to have my drivers seat electrics working


Scott

Hello everyone! Can someone pleae help me locate exactly where to find the fuse to repair for the seats to work? I located the small, fuse box in the trunk and also took off the carpet & black cover with the 3 screws but havent found any fuse box! I'm sure its right underneath my nose....

Thanks for the help. I am selling my car & need to get it working asap.
THANKS AGAIN!

jennifer

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.

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!!!