2006 Malibu blower intermittently works, low fan stays on and drains battery

SOURCE: 2006 chevy silverado blower fan

With one speed working it is more than likely the blower motor resistor (20 dollar part) located in the area of the blower--needs air to pass by it as it gets rather hot), or at worst case the Module. This part (Blower control Module) is a bit more expensive. Try the resistor first, you can test its resistance at different speed settings to see if it is functioning as it should.

SOURCE: 2006 Chevy Trailblazer heater/ac blower

Did you check for a burned out fuse??

SOURCE: Heater/ac switch speeds 1 and 2 don not work in 99 Silverado

you need a resister found under your air duct by the passenger floor under dash board auto zone sells these for about 25.00 you may as well buy cabin air filters while your at it . 1 of the screws will be a pain to install back into the duct work I left mine out didn,t make a difference . you might have to order it as they are a comman item oh you will need a vacuum to clean up mess from cabin air filters .this is not a hard job .

SOURCE: ON A 2001 CHEVY MALIBU THE BLOWER FAN ONLY WORKS

The blower fan uses a multi segment resister to control the fan speed, it is generally mounted just under the blower in the ducting. The reason 1,2 and 3 are not working is, sections of the resister is burnt out. The lower speeds are the first ones to go since they get hotter due the higher load in soaking the unused power. Resister is around $20. look for blower resister.

SOURCE: 97 blazer s 10 heater blower fan stops working

Blower motor is probably at the end of its life. I'll guess that it probably works best when it is cold, then when the weather, or the fan, is hot it quits working. Same issue with my cars when the fan got old and tired. Dealer can get you an expensive new one, auto parts store can get you a less expensive new one, or the salvage yard can get you a cheaper used one. I recommend www.car-parts.com to find a yard close to you with the part.