Sorry forthe long post
READ EVERYTHING COMPLETELY AND DO ALL MODIFICATIONS AT YOUR OWN RISK !!!!!
Parts Needed:
1-single pole single throw switch (suggest one with a light in it)
1-single pole double throw relay and socket if it doesn’t have a pigtail (wires) coming off it (Bosch and other names) used in many applications of other vehicles available at most auto parts places
16ga wire in different colors or label them
First locate the solenoids that control your 2wd and 4wd they are under the hood on the passenger side fire wall this is where you will be running the wires to from the relay. This process will require cutting these wires.
After that locate where you want your switch (I located mine in the blank area just under the radio) and where you want to locate the relay ( I located mine in the kick panel on the passenger side) but depending on the relay you buy they can be located under the hood if you want to have it there.
Next mount switch and run a switched 12v supply to it (one that will turn off with the key) this is IMPORTANT that it is switched so make sure it does before going any further!! The other side of the switch will go to the white output wire on the relay. Also hook up ground wire if your switch has a light.
Now for wiring the relay, first hook up (Black) wire coming off the relay to a good ground, next hook up (White) wire coming from the switch, The remaining wires (Red,Blue and Yellow) will being getting hooked up to wires under the hood at the solenoids.
First carefully strip back enough insulation far enough away from the plug that you can work with it on the Black with red tracer(B-R) wire coming off the 2wd solenoid and connect the (Yellow) or normally open side of the relay wire. If you end up cutting this wire into just connect all 3 wires together.
Now is when you decide (AGAIN) if you want to really do this cut the Black with white tracer(B-W) wire coming off the 4wd solenoid into far enough away from the plug that you can work with both ends. The side from the solenoid will be connected to (Red) or normally closed side of the relay, the other side of this wire will be connected to the (Blue) or common side of the relay.
Shrink tube, seal or tape all connections !!!
To test/use out your new 2wd switch you must be in neutral and stopped of course (NO SHIFT ON THE FLY) and have your transfer case shifted into 4wd low NOW TURN ON THE SWITCH you now have 2wd low !!