Depende kasi sa motor mo....old motors na wired up with a single wound kung tawagin will need resitors to lower the power intake nito so babagal ang ikot ng motor. Kung walang resistor (ang itsura nito usually ay wire na naka-coil lang at nakamount sa isang white ceramic spacer) baka ang motor ay multi-wound (parang electric fan so ang low speeds will have its own power line) so hindi mo makita ang resistor.

Kung DIYer, start from the panel ng switch. Get a continuity or multi tester and itest mo muna ang switch kung hindi sira. Then trace the wires upto the blower motor baka meron putol. Until ma-isolate mo kung motor nga problem. If kaya mong i-dismantle ang blower fan nito and find that it have more than 2 wires protruding from the motor, yan yung motor na walang need for a resistor. Test all these wires (one should be the ground) kung ok ang continuity and if the motor starts when power is applied. That is a 12v motor so you can tap it directly sa battery to power it up.

HTH