S203 c270cdi

motorsiklemad

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C Class W203 / 2005 / 270cdi
I have a 2005 S203 c class 270cdi which I am having problems with the fog lights not working when switched on using light switch. Does any one on here know the procedure for testing the light switch? Parking lights work, side lights work,dip and high beam also work fine. Just the fog lights front & rear that are not working.
 

mersum1es

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W212/-09/350CDI, W219/-07/320CDI, EX:W220/-01/320CDI, EX:W211/-04/320CDI, EX:W210/-01/270CDI
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motorsiklemad

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C Class W203 / 2005 / 270cdi
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The Fog Lights do not have a FUSE allocated to them they are controlled through the SAM unit attached to the fuse box. I also know that there is not a wiring problem as the front Fog Lights work when I lock the car so bulbs etc are fine. I'm thinking I need to test the light switch, just can't seam to find the information that I need
 

mercedes13156

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CLK 200 Cabrio and a Ford Kuga
The easiest way I can think of testing the switch is by putting the car on diagnostics and testing the function of the light switch. If I recall correctly, you can see all of the switches on live data and it shows something like.....

Circuit Name and "Activated / Not activated" when you turn the switch.
 

mercedes13156

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Correct. The only other way is trial and error with a multimeter....

After having dismantled the car to get it out and released enough cable to turn it over so you can get the probes in. That in itself is worth the cost of a session.
 

mersum1es

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W212/-09/350CDI, W219/-07/320CDI, EX:W220/-01/320CDI, EX:W211/-04/320CDI, EX:W210/-01/270CDI
oops sorry, was thinking W210 fogs... there they are fused, and in addition there is some resistor kind of element before front fogs which brittle in time... W203 it might be light switch related, it should be not difficult to take apart and check wirings
 


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