If they make a led bulb to fit your application, it should work alright as the led puts out less heat than an incandescent bulb.
Exactly. It seems they tried to simplify the diagrams in 2002. They failed.If you look at the front park,turn lamp, it shows 2 wires but has 3 places for connection. 1 is blank. Furthermore, if you look at all the exterior lighting diagrams, you will see the blank spot is now hooked to a brown wire and where the light blue or dark blue wire was, is now a blank spot in the diagram.
Same for the rear park, turn lamps, they are only showing 1 circuit at a time. You will have to go to another part of the exterior lighting diagrams to find the other part of the circuit.
I don't know why GM did the diagram that way, but it can be confusing. Rest assured that park, turn lamps do indeed have 3 wires to them.