I fitted DRL's to my car and didn't need to touch any of the cars wiring to get them to come on automatically, the only thing I did have to do was a small nick in the sidelight wire, to wrap the "lights off" wire.
Basically, all you need is a
- piggy back fuse adapter
- speaker wire (optional)
- on / off relay (around a tenner) http://www.ebay.co.u... relay&_sop=15,
- male / female spade connectors (or butt connectors) to join the wires
- Electrical tape
Simple installation really, take the relay positive, and wire it into the piggy back plug. This will be plugged into the auxiliary fuse box and piggy backing off one of the "Engine Sensors" (you should use a 3amp fuse for the DRL). This means that it comes on when the ignition is on and off about 30 seconds after the car is killed
Take the negative, (if necessary. extend with speaker wire) this will then attach to the earth point, or the negative terminal of the battery.
Take the DRL live wire/s and wire these into the DRL positive output, then do the same for the negative.
Take the "DRL Off Wire" and locate the sidelight wire in the harnass leading to the headlight. This is normally orange / green on the nearside IIRC. Then with a pen knife, place the knife under the wire, and your thumb on top, then rotate the knife gently, but firmly around the wire to score the wire. With a finger nail, just pull back the sleeve to reveal the sidelight wire. Wrap the metal of the "off" wire tightly around the bare sidelight wire. I would suggest testing everything works, before the final stage, which is to wrap electrical tape securely around the joint, and then test again.
Plug it all in and jobs a good 'un.
Took me longer to decide where to to route the wires than it did to wire everything up.