relay diagram for w203


EDIT: Please request a copy of the Star findings. You will be paying for it.
Last edited by Glyn M Ruck; Dec 15, 2011 at 03:39 PM.
I just wanted to follow-up and thank you for your assistance.
I had parked the car in the garage and avoided it for awhile, but the wife was not happy.
I am glad to announce that I have "Lights"!!
It was the swithch after all. I took it to a dealer that works exclusively with MB's and had the Star capapbilities. After he checked all codes, and there were a few sicne I had disconnected the battery he noticed the the switch was a salvage part which I also noticed. There was a pin or two broken in the switch and he ordered a new one. We now have lights!! and the wife is happy, which makes me happy.
Thhanks again for all the help.
Hi
I have a C320 2001 and it has problems with the turn signals, wipers, horm and the instrumental cluster not working properly. They worked intermittenly. I can not change the function on the cluster. The cluster also shows error of tail lights "bring car to shop" but both are working good. I checked the fuses and they are OK. Replaced the front SAM unit but the problems could not be fixed. Does anyone have any suggestions? The car is running good except these problems.
Thanks.
Last edited by babenzforum; Nov 4, 2014 at 10:01 AM.
how about the rear SAM problem? Any idea?
Thanks
how about the rear SAM problem? Any idea?
Thanks
Electrical gremlins are PITA even in cars without CANbus. We can tra a couple simple things - then it's off to STAR diagnostics. Lots of luck with it.
The Best of Mercedes & AMG

It sounds as though you have a cluster or CANbus problem. You need to get this car onto a Star for a full diagnosis. You say you changed the front SAM. Who reprogrammed it for you?
Cluster & CANbus problems are not DIY unless you have your own Star.
It sounds as though you have a cluster or CANbus problem. You need to get this car onto a Star for a full diagnosis. You say you changed the front SAM. Who reprogrammed it for you?
Cluster & CANbus problems are not DIY unless you have your own Star.


Wiki access is messing around at present. Will try & have fixed.
Bob
You have 3 fuse points in a W203. Driver's side of dash. In the front SAM & in the rear SAM. Your fuse etc. diagram s/b in the driver's side of dash fusebox.
You have one SAM in the rear engine compartment opposite side to the battery under a little water cover with twist fasteners & then under a cover with lever snap fasteners. The rear SAM is in the trunk on the LHS under a cover in the trunk lining.
Light activation is by the SAM's themselves when they receive a signal on the CANBUS. They are electronically protected - no fuses.
I hope you don't have blown SAM's as they are expensive. Lets hope they just need reprogramming or similar.





Fuses are not needed with this arrangement. The measuring circuit not only allows protection of the wiring much faster than a fuse, it also allows a lamp out warning, and can sense over current conditions (like a failed lamp) that would not be protected by a fuse.



They rarely fail, are you sure it is not a bad starter solenoid or starter itself? Have you checked the heavy gauge wires to the starter for condition? The latter are more often pits in the path of progress for starter problems.
Fuses are not needed with this arrangement. The measuring circuit not only allows protection of the wiring much faster than a fuse, it also allows a lamp out warning, and can sense over current conditions (like a failed lamp) that would not be protected by a fuse.
I have 2002 c230 (w203) and had AC problem a few days ago, it started blowing hot air. I noticed that the fan is not working when AC is on. When I start the car and keep AC off, the fan spins slowly. When I turn AC on, it completely stops.
According to what I read above,
- fan control unit
- fan relay
- front sam
- or pressure sensor
might the cause for this problem. Is there any other possible reason? Can anyone explain how to identify or how to check what the cause of problem, with a language that someone like me who is not a mechanic can understand?
Also just noticed that viper is not working too. Is it about relay or anything else?
I appreciate if you can support your solutions with some pictures or diagrams.


