See the original thread here
http://www.grandprixforums.net/f71/h...hts-22162.html
I did this in my 2008 grand prix so i could run HIDs, it may work in earlier models as well. This is for grand prix's that have headlights as daytime running lights.
I ASSUME NO RESPONSIBILITY IF YOU MESS THINGS UP.
DO THIS AT YOUR OWN RISK
This will void your warranty!!
PLEASE READ CAREFULLY!!
first thing you need to do is remove the panel on the side of the dash, the BCM is located here
once you have that panel off, remove the small kick panel underneath the dash, it's held in by 3 push pins, twist the foot well light to remove it. once you have that off, remove the radio bezel
remove the 3 screws that hold the dash panel in and pull the panel straight out.. now you will see 3 screws that hold the BCM in, remove them
unclip the harness from the left side of the BCM, it may be zip tied, if so cut the tie.. THIS HARNESS IS NOT USED.. once that harness is out you can pull the BCM out from underneath.. unclip both harnesses from the bottom.
carefully cut away at the electrical tape and expose the wiring on both bottom harnesses..
locate pin #7 (WHITE WIRE) on the smaller harness. see diagrams below
Use a wiretap to tap into this wire and connect it to pin 85 on your relay
Now locate pin #9 on the bigger harness (PINK/WHITE WIRE) see diagram below
CUT this wire and crimp on female connectors to both ends.
ignore the wiretap on the white wire DO NOT use the white wire.
Connect the wire from the BCM harness side to pin 87 on the relay.
Connect the wire coming from the firewall to pin 30 on the relay.
Now you need to find a constant 12 volt source, i used the radio harness, but any constant 12 volt source will work.. Run a wire from pin 86 on the relay to the 12 volt source.. and thats it, you're done. no more DRLs
final product, make sure your connections are tight and tape everything back up
pinout diagrams