iva had my car for about 6 months and the AC/Heater worked fine, then all of a sudden it started acting up, wher on l settings 3 and 4 on the fan speeds worked and 1 and 2 didnt. anyone have any idea of what might cause that or is my whole block shot?

 

Sounds like the HVAC control (heater a/c switch) is broken, or you have disconnected some wires while doing repair work. Try swapping in a new heater control (or testing yours with a voltmeter) and see if that helps.

 

alright thanks. im going to try that out. where exactly is the HVAC control?