I rescued from my neighbor's curb a Central Pneumatic 150psi 6gallon 1.5HP Compressor Item #67696. Of course I know some folks think "Harbor Freight throwaway item" but I can't resist a challenge. Sometimes the electric motor starts/runs and sometimes (actually most of the time) the electric motor will not start/run. I have completely bypassed the On/Off switch and I have bypassed the Pressure Cutoff Switch (i.e. I have wired directly the 110V AC power cord to the motor).

What is likely to be the problem with the electric motor? Do bad brushes typically cause a motor to not start/run? Dirty contacts on the armature?

Any/all input will be appreciated.

Thanks skatingtoolman for the response.

It does not hum when it doesn't start, nor does it kick the breaker. It just does nothing at all. I have already bypassed both the Pressure Switch and the main On/Off Power Switch, i.e. I wired a 110V power cord directly to the motor. Black to black, white to white...

I didn't/don't see a Model Number. I could be wrong but I believe Harbor Freight uses Item Numbers instead of Model Numbers. Per original post this is Item #67696. thanks!

I noticed that the motor would run if I gave the fan or any other rotating part a slight "nudge" in the correct rotational direction. I also noticed that the bearings on motor, pulley shaft, etc had a gritty feel (this compressor was in my neighbor's shed during recent hurricane/flood) . So I disassembled as best as I could and lubricated all bearings with SAE30. The motor starts and runs OK now. I only need to replace the missing 1/4inch NPT Male Hose Quick Connect fitting to then perform a full functional test.

Thanks again for advice and "sanity check".