Gas and Oil Home Heating Furnaces - carrier Crusader no heat no fan

I have a model # 58DHC040-EC, Series 100, which makes some noise when I activate the thermostat, but no air is flowing. A tech came out and said I need a new blower unit ($500), but I'd like to check a few things on my own first and make sure. Also, where's the bestplace to buy parts (SF Bay Area)?

Try to put the fan switch on the thermostat on on instead of auto this won't tell you conclusively whether or not your motor is bad but if it blows you will know that you probably have a problem with you fan control (relay or board).
If you access the blower compartment with the power off and the motor is trying to run and it is getting power it maybe warm to the touch this could be bad bearings or a weak capacitor.
If you decide to replace I am not familiar with suppliers on the west coast but national chains are ww grainger or marcone but there are many others you can find online just type in appliance parts or yellow pages under appliance or air conditioning or heating parts

The OEM Carrier distributor is "Totaline" Supply CO, however if the unit is over five years old you'd probably be best suited for a generic replacement motor vs the expense of the OEM (try Johnstone supply). Just out of curiousity why don't you believe your A/C service tech, he should be an expert in that field? If the unit is under five years old then it is likely under a parts warranty which would mean you get the motor at no cost. You can certainly check the capacitor and relay board but motor diagnostic is HVAC 101, your tech is probably correct unless he was really inexperienced.
-B