there is another option. granted, i havent done any testing with this, but in theory it should work.
there is an illumination wire in the doors. its what powers the lights around the window switch when the parking lights are on. im not sure of the color yet, but there definitely has to be one. you could tie into that instead of the marker lights, however they will not stay on when you open a door like the marker lights do. you may also need a low voltage trigger to power a relay. but this is how i would wire it.
85 goes to the turn signal wire.(if you need a low voltage trigger, this is where it would go inline.) 86 goes to ground. 87 goes to ignition (also found in the door) and 87a goes to the new lights. 30 is not used.
what this does is puts the circuit as normally closed so the ignition power will pass through the relay allowing you to have them on with the parking lights. and when the turn signal is pressed, it will trigger the relay to flash. the one issue is that it will be reversed compared to your turn signals. the only way to make them flash in unison would be to run wires into the cab. having a dual purpose light makes for extra wiring unfortunately. this may or may not work, but maybe worth a try before you pull a door off.
there is an illumination wire in the doors. its what powers the lights around the window switch when the parking lights are on. im not sure of the color yet, but there definitely has to be one. you could tie into that instead of the marker lights, however they will not stay on when you open a door like the marker lights do. you may also need a low voltage trigger to power a relay. but this is how i would wire it.
85 goes to the turn signal wire.(if you need a low voltage trigger, this is where it would go inline.) 86 goes to ground. 87 goes to ignition (also found in the door) and 87a goes to the new lights. 30 is not used.
what this does is puts the circuit as normally closed so the ignition power will pass through the relay allowing you to have them on with the parking lights. and when the turn signal is pressed, it will trigger the relay to flash. the one issue is that it will be reversed compared to your turn signals. the only way to make them flash in unison would be to run wires into the cab. having a dual purpose light makes for extra wiring unfortunately. this may or may not work, but maybe worth a try before you pull a door off.