How do I wire DRL headlights properly

It might help if you mentioned:

• The model year of your Mustang.
• The fuse that you used to tap into.

1999-2004 MY fuse panel schedule:

Finally. Why not learn how to perform the wiring correctly? Solder with heat shrink tubing.

Use an "add a fuse" or "add a circuit" to tap into the car's electrical instead of modifying the car's factory wiring.

Use automotive grade wiring so that heat and weather doesn't degrade the insulation.

Leaning a new skill can is always a benefit. Do the job right first time. One time.

Signed.

Ward Cleaver