2003 G500 Drivers Fog Light Help please

[Trayder]

Drivers side fog light on our 2003 G500 is malfunctioning. The bulb is not getting 12VDC I ran a continuity test on the ground and it checks out to the frame so I figure it is a bad wire on the positive side or a fuse?

I can not for the life of me locate the fuse I downloaded Vlad's excellent electrical diagram but there is no mention of a fuse for the fog lights. I did however check all the fuses I could in the drivers side and under the passengers side and non are blown out, from what i can see.

I am seeing 12VDC pulses??? when I hook my voltmeter to the connector side as seen in the following video that looks like a signal from the diagnostic bus but i am not sure I do know it is driving me out of my mind......

Any ideas?

YouTube - g500fog.MOV

[fernweh]

Originally Posted by Trayder

Drivers side fog light on our 2003 G500 is malfunctioning. The bulb is not getting 12VDC I ran a continuity test on the ground and it checks out to the frame so I figure it is a bad wire on the positive side or a fuse?

I can not for the life of me locate the fuse I downloaded Vlad's excellent electrical diagram but there is no mention of a fuse for the fog lights. I did however check all the fuses I could in the drivers side and under the passengers side and non are blown out, from what i can see.

I am seeing 12VDC pulses??? when I hook my voltmeter to the connector side as seen in the following video that looks like a signal from the diagnostic bus but i am not sure I do know it is driving me out of my mind......

Any ideas?

YouTube - g500fog.MOV

I believe all of the lights are controlled by electronic control units (ECU) and are not individual fused. This system should be able to notify you with an alert message if a bulb is burned out. Also the ECU shuts down the +12V to a specific light/bulb if a defect or problems has been detected. Normally after recycling the ignition the power is restored, unless the electrical fault is detected again
With the MB Star Diagnostic system you can troubleshoot each light by itself.......
Try to install a different foglight bulb

[Trayder]

Thanks!

I tested the bulb that was "malfunctioning" and it lights up just fine I also swapped with the other side, it works fine and still nada.

I appreciate the insight on the ECU that explains the lack of fuses, is there a way of "resetting" it?

[Trayder]

Scratch my last reply....I re-tested and waited a bit longer after switching the bulbs and sure enough it works. It was the bulb all along.

Now I have to figure out how I triggered the ABS light during all this messing around.....always something

tx for your help
J

[fernweh]

Originally Posted by Trayder

Scratch my last reply....I re-tested and waited a bit longer after switching the bulbs and sure enough it works. It was the bulb all along.

Now I have to figure out how I triggered the ABS light during all this messing around.....always something

tx for your help
J

Yes, I know.......same thing happened to me with the front right side marker light.

ABS light might have been triggered by overall low system/battery voltage