Originally Posted by Yugguy
for ref here is where my drls are grounded. They are the black wire, the brown are other earth wires already there.
I assume your DRLs have a red constant power, an Ign. ACC + (red or other colour), and the black for negative.
And I guess some switched wire to monitor if the side/headlamps.
One intriguing point with the Philips Technical guy (who I found seriously underwhelming).
He insisted the black must go to the Battery neg. Despite explaining the Mercedes technician advised to put the black negative to the VEP, (so the BCM / Battery sensor knew about it).
So I asked him what is the difference to your unit, of grounding to the body or the battery negative post. And he just wouldnt answer, just kept repeating put the black on the battery negative.