I have another link that did this.... (if you have puddle lights this is real easy)
Courtesy of Iamsuperbleeder (stole it sorry it)
Originally Posted by mtunender
Anyone know how hard it would be to make them work like marker lights also.
I just wrote this up on another forum for someone else this morning...
You totally can do what you want but it requires an added level of complexity. Here's how to do it:
First, you'll need the LEDs, wire, wire connectors, 2 1500 ohm resistors and 4 4001 diodes. (You can experiment with the size of the resistor to allow the parking lamps to be brighter or dimmer if you choose. 1500 is a good starting place). The parts combined (with LEDs) will cost about $25 (the LEDs cost me $20 at AutoZone).
From your newly installed LEDs, splice off the positive wire to form two positive wires in the form of a "Y". (See pic below, it'll make more sense).
On one side, add a diode (the colored stripe should be closest to your LEDs) and attach to your existing turn signal mirror.
On the other side, add the resistor, then a diode, then attach to the wire you found in the kick panel or under the hood for the parking lights. (This is the hard part - I hate running wires in to the door jam).
Ground your LED and test.
Think of the diode as a 1-way street, allowing electricity to flow through in only one direction. This is the key component to allowing you the ability to turn on the LEDs from multiple sources. The resistor simply acts as a dimmer switch.
This image has been resized. Click this bar to view the full image. The original image is sized 802x215 and weights 28KB.
Note: I didn't do this to my truck because I didn't want to run the parking wire in through the door jam. Likewise, I think it would look cooler if only the outside 3 LEDs (I have a total of 9 on each mirror) light with the parking light, not the entire thing. And finally, I decided that if I was going to do it that I'd add a puddle lamp to the bottom of the mirror housing at the same time (but I don't have puddle lamps to install right now). No point in pulling wires through the jam and not getting them all done at once.
I have, however, used this method for other wiring projects in the past and know it to be tried and true. The resistors and diodes are much easier than using a relay, which also would work if you're familiar with them but they require additional wires. With that said, I don't take any responsibility if you try this and it jacks your truck up. But using this will allow you to enable all the LEDs with your parking lights and your turn signal.
Link to old thread doing it the hard way...