Why does my a/c climate control fan only work on high?

have a 1988 oldsmobile cutlass supreme v6 2.8L 2dr coupe my A/C works just fine and is cold, however the climate/fan settings control switch on works on its highest setting. there are 4 levels of fan blower settings, the 1st 3 settings don't work at all, suddenly. i can still use A/C but on the highest setting only. it gets so fricken cold so fast so i always turning it off/on. i used to be able to just set the fan blower on 1 or 2 and i'll be ok. well the car came with 4 settings and they used to all work, now only the 4th/highest setting is available. i want to know why the other 3 fan(speed)blower settings don't work, what could've caused it, and HOW CAN I FIX IT INNEXPENSSIVELY.





~I DO MY OWN MAINTENANCE, REPAIRS, MECHANICAL, AND CUSTOM MODIFICATIONS WORK ON MY VEHICLES. HOWEVER I CAN NEVER STOP LEARNING, AND I NEVER SAID I KNEW IT ALL. I LIKE TO GET POSITIVE INPUTS 1ST, MAYBE A GUIDE BEFORE I JUMP INTO STUFF. THANK YOU FOR YOUR HONEST KNOWLEDGEABLE INPUTS Why does my a/c climate control fan only work on high?
the car needs a new blower motor resistor the reason it work on high is because high has no resistor thats why its called highWhy does my a/c climate control fan only work on high?
The HVAC module is bad. GM is famous (or infamous) for this type of failure from the eighties all the way into the mid nineties. Repair is simple -- just replace the climate control switch unit, but usually costs over $200!
The blower module/resistor is burned out.
The first two guys are on it.