I did it in my 84 ive heard its alot easier in an 89-95 body style go to the auto parts store they sell i think theyre 1159 bulb pigtails its a gm double filament bulb style and you can un hook the blinker harness and bring it up thru the fender to the marker light. Since i have an 84 i have less room i used a piece of pvc and plastic welded it to the inside so i could fit the bulb i used the threaded one so the teeth on the bulb socket had something to hold it from popping out. Hope that helps if you need pics i could probably post some up
Wait don't make any more holes, you can use the stock bulb and tie into your bumber light + to make them alternate. I'll have to find it when I get home.
wire the side marker ground wire to the parking light hot. http://www.painlesswiring.com/Manuals/20112.pdf I know it sounds crazy but the light will seek a ground and when both sides have positive the light turns off. I wish I had my side markers still I would post the pics of what I did. Learned this back when My brother put a harness in his Camaro.
Yes, a number of cars were wired from the factory like that, late 80s/90s domestics i think. I'll. Just run the ground of one bulb to the + side of the other. the parking lights ground through the turn signals but limit the current below what turns them on. I will qualify this in that I did this from memory+electrical knowledge NOT experimentation on my truck. The numbers match up but I have not tested it. The result is: Parking lights on/turns off: parking lights on parking lights off/turns on: turn+parking lights flash parking lights on/turns on: park & turn lights alternate.
Get a socket with three contacts with matching bulbs, might as well order LED's. Ground and Parking lights run to the "low" contacts, turn signal into the high contact. Boom, done.