Blower motor resisters are usually what people run to first and are the easiest thing to swap out but (and no offence frankie) dont just go throw parts at it. Does the fan blow harder on each progressive setting? If it does its not the resistor. Next, check ur cabin filter. This being clogged stops the air needed from being sucked into the system, thus limiting what the ac will put out. Next, flip your controls from max ac to normal ac with the radio off doors and windows closed. If you dont hear what sounds like a flap clapping back and forth you need to check your temp door. This directs all the air across the ac condensor, cooling it off as much as it will allow. The condensor looks like a radiator under the dash. Check these then report back. We will help as much as we can.