The DRL bulb sockets tend to fry over time, so check the contacts inside and maybe bend them out a little. If the bulbs are LEDs, turn them 180° and reinstall; I believe they're polarity-sensitive.
To test the DRLs in daylight you can chock the wheels or set the parking brake, turn the ignition to run -- without starting the engine -- and put the shift lever in Drive.
To test the DRLs in daylight you can chock the wheels or set the parking brake, turn the ignition to run -- without starting the engine -- and put the shift lever in Drive.