Run jumper wires from battery to blower motor bypassing the switch and resistor to see if motor works if it does then then use voltmeter to see if power is reaching the resister if not use voltmeter to see if power is making it to switch, if not find fuse & replace. If power to resister check for power leaving it if not replace resister, if power is making it to switch but not leaving switch then replace switch. If power is reaching every component and blower motor is not running and no relay on the older models then replace blower. You can also instead of using a voltmeter us jumper wires around each the switch and resister to rule them out too.
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