Hey i know how to do the mod but i was just wondering if i could get all four sets of lights to come one at once. if so could anyone just tell me which ones i have to connect. on yeah i also want this to happen when the high beams are turned on. thanks

 

I wrote up the mod on how to do it, but what year is your truck? The mod I wrote is for the 03+ trucks(not sure if it works on the 05+, but assuming it will). Do a search and you will find the mod for the 99-02 and the one for the 03+

Good luck

 

I did the the mod that 04BlackSilverado wrote up on both my 03 and 06. Real easy and cost under 2 bucks.

 

ok cool but u guys think that the 99-02 trucks are different? because i have a 02

 

The 99-? (maybe 02) have a negative high/ low beam switch. I am about to do a 4 headlight conversion on my truck, when I get around to it.

My current idea uses 3 relays and 12 gauge wire for the headlight power feed and 16 gauge wire for the signal wire for the relays.

Relays
1 - low beam
1 - high beam
1 - turns the low beam on when the high beams are on

There is also a method of using a diode but I am not too convinced about this method

This is oem wire color;
orange - +12V
yellow - low beam, this wire goes to the ground through the headlight switch
purple - high beam, this wire goes to the ground through the headlight switch

 

All you have to do to get 4-hi on a 99-02 is ground one wire under the engine compartment fuse panel.