TN AV03 said:
"There is an updated Full Time DRL mod for the '03 coming that retains the use of the headlight switch for turning them off and also makes the work with the key fob for night time keyless entry.
WesTexAvy And Sovereinmgmt have it done, I'm doing it tomorrow for testing purposes. After we know it's ok, I'm sure Chris will post it for everyone."
Still waiting for the post on this for my '03
WesTexAvy and Sovereinmgmt, any updates
Sorry for the delay with this
2003 Better Method DRL/NRL mod. These instructions are for the
2003 Avalanche ONLY! so here we go................
Shopping for parts:
At Radio-Shack you will need to take $3.00 with you for some 50 volt/1 amp diodes and a pack of ScotchLok Tap connectors.
Diodes : RS part #276-1101 (1N4001 Industry #). This is a pkg. of 2 for 59 cents. I believe all Radio-Shacks have gone to the big metal drawer/bin cabinets for these items.......if so these diodes are in drawer #B-1
Red Squeeze Tap Connectors: RS part #64-3053. This is a pkg. of 7 for $1.99. These are in drawer #B-13. (These are actually 3M brand Scotchloks).
**
Edit: See post #239 below for issues resolved when using these tap connectors**
Modification Theory and Results:
2003 DRL/NRL mod using a diode keeps (or takes the DRL back to) it's original circuit relay and fuse with modified control. The DRL works as factory except at night it takes a relay trigger from the Park lamp relay so this does 2 things:
1. DRL lights on at night and , 2. using the Headlight defeat (manual off) position of headlight switch turns everything off.
Tools Needed:
13mm Socket and pliers. (7mm nut-driver
only if you need to REVERSE the prior DRL/NRL mod of moving the blue wires)
I don't want to make this post longer than necessary...so I will just link to prior information already posted. Sorry for bouncing around for info
.
Gaining access to it post. DISREGARD PICS IN POST #119 IF YOUR HAVE
NOT DONE THE "MOVE THE DRL WIRE MOD"
If you DID do the "2003 Move 1 wire DRL/NRL mod", you must REVERSE it now. Refer to the
Move 1 wire post for pin location.
The Better Method DRL/NRL mod:
1. Connect the Cathode side (white stripe) of the diode to pin #F11 White wire on the C1 white (light grey) block with a red tap-in connector.
2. Connect the other end of the diode to pin #E3 Lt Green w/ Black stripe on the same block with another tap-in connector.
If you would like to do the "All 4 Headlights on High" mod, you might do it now since you already have the parts and you are in the same wiring location
Follow this
2003 Diode for All4onHigh post for instructions.
**For the 2002 Avalanche, I was not able to achieve this mod at the under-hood fuse block...I did achieve this mod at the under dash BCM location. Now I am not a fan of any wiring mods in this location for various reasons....so I don't think I will post this info until I come up with a better location for the mod
.
Did I mention that this is for the 2003 model and not the 2002 model I am sure this violates vehicle codes in various states, and may result in a traffic violation or vehicle inspection failure (you bunch of OUTLAWS 
). I would like to stress my favorite XRover WARNING below also applies to this post:
XRover said:
This mod I am sure will void the warranty but unless someone is actually looking underneath the electrical box, they will never see it. Please do not attempt this unless you are VERY competant and knowledgeable in electrical systems and using a multimeter.
............I am in no way telling anyone to attempt this. If you understand what I have done and it makes sense to you then you can do whatever you want.
If it is a bit confusing, please don't attempt this because you can fry your electrical system if you tap into the wrong wire.......
If you think I am just plain crazy,
Get in line...
I know I'm not this stupid, but what is left out everytime with all these directions is where to start. I refuse to do the under knee bolster soldering mod. 
Thanks to everyone on this board....I now have full-time DRL'S 
