blower motor speed switch

On my 02' Jeep Liberty Sport The a/c and heat work just fine. My problem is with the blower motor fan speed. At first it only worked on 1,2, and 4, now it only works on 1 (low). You can set it on 2 3 and 4 it will run on all of them but only on low speed #1. Is there a "speed relay" or do I need to change out the fan speed switch on the dash ?. When I look at auto parts store it only shows a/c heater selector switch which has the speed control , temp. ,AC heater selector , and the rear defrost button switch on it for $100.99. Does it all have to be changed out or can I get just the fan speed selector switch ?? HELP

This might help.
http://www.jeepkj.com/forum/f202/how-replace-blower-control-resistor-block-26012/

where is the Blower Control Resister Block located. 02 jeep liberty sport 2wd.

Click the link in his post. Links on this forum are grey and may not appear clickable.

Then read post #2 and follow the steps in post #4.

It's an easy fix.
over 80,000mi and no failure of ours yet.