Daytime running lights are typically your high beam lamps. A voltage less than 12v is run thru the circuit.
If you can determine which wire feeds the running lights, you can back trace it to the relay that turns them on. The relay turns them off when you turn on the headlights. Try using a non-contact voltage tester to determine which wire is supplying voltage to the running lights. Klein makes a good one (NCVT-2) for about 10 bucks (Amazon or Harbor Freight).
Lastly, if you're having a problem with your low beam lights, the running lights aren't causing it.
What problem are you trying to chase down?
It ain't easy being me...I've tried.