99 civic blower fan problem

my 99 civic Lx blower fan only work at high setting. the car has only 100k miles. I've changed the fan blower's resistor or transistor and still it doesn't work right. On low speeds, the motor spins but very slow, not like before. you can barely feel the air going through the vents. So basically it's max warp speed or nothing. Any info. you can provide is greatly appreciated. I bought that resistor from a honda dealer, so it's authentic. I am just thinking the only thing left is the switch is going bad or the motor.

TIA