T1 is black-white and is High beam control- tap into this and run to a spst (2 terminal) switch, if you are going to use a switch to disable this mod. On the other side of the switch solder 3 diodes with the band ends towards the switch. I used 1n4005 diodes. Now for each of the other ends of the diodes you will solder a short length of wire on and tap into these leads as follows:
T4- is green black and is DRL control
B4- is pink and is low beam control
B5- green white and is fog lamp control
When you're done make sure to insulate each of these ends of the diodes and wires from each other and everything else. Start the truck,turn the headlights on if it's not dark, and with you're new switch off everything should work as before, or as normal. Turn the switch on and with you're high low beam lever in the low position you're low beams and fog lamps should work as normal. Flip to high beam and everything should come on. All we're really doing here is operating the relays under the hood that turn these lamps on normally. There should be no problem with power as they are still getting power the factory way. My only concern is the grounds on the headlamps, I'm hoping they don't run too warm running both lamps at once, and I don't know if both lamps are grounded together or if they have individual grounds. I may have to upgrade the grounds if they give trouble. Hope this is somewhat understandable!Click on image to open in new window
Further note- if you are testing with the ignition switch off the DRLs will not come on at all, that's why I said start you're truck in the testing. If you don't want to install a switch to bypass this mod just connect the band ends of the diodes directly to the T1 black white wire.Edited by: Kyle03D
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