THE LAST 2 SPEEDS ON MY 2000 JEEP WRANGLER BLOWER FAN DOESNT WORK.

Replace the blower motor resistance it controls the fan speeds.

you have a bad blower resistor

Wire is too small to handle the amps of the blower. See if wire is burnt.

Yes I would go with the switch, BUT, does it have a resistor bank? That is, how does it reduce the speed? Many systems use resistors to lower the speed. Burnt or bad connections can cause this as well.
You can test the blower motor by connecting direct power from a source like the cigarette lighter if you are handy.
Most of the time the lower speeds konk out but the high speed continues to work this is the resistor bank that goes out.

BJ
I'm using the comment section of the original posting to communicate with you.
Pat

If you bypass the resistor pack and connect the motor directly to the fused 12v supply then the fan should run at maximum speed. If so, it's the resistor pack that's blown: a very common fault on a huge number of makes and models.

You probably do need a new switch, but check all the connections between the switch and the resistor pack first.
(These blower motor supply wires carry heavy current - commonly, a loose or poor connection will overheat and fail).

thats is two different problems. the blower motor resistor is bad causing it not to work on the lower setting just high. now on the defrost not working could be the blend door actuator but to figure it out you will need to be diagnosed by a professional. it is a little more involved. but the blower resistor is fairly easy

let me know if you have any ore question

if fan speed is working only on one speed it is most likely the blower resister,located in the blower box