2009 Jetta Main Cooling Fan on 2040-parts.com

I have for sale a used cooling fan from a 2009 Jetta Sportwagen TDI.  It is the original part shipped with the car.  The fan operates, but stops intermittently for unknown reasons.  I replaced it with a new one, and the new one operates normally.  A technician from Ross-Tech suggested that it may be a problem with the electronics in the fan motor that occurs only when the fan gets hot from the engine.  I can't verify this is what's happening.  I opened the fan motor and everything looked to be in really good shape, and the brushes have plenty of life left (it was taken apart before I had the replacement, it was reinstalled, and the fan worked the same as before disassembly).  Maybe can be used for parts, don't know if it can be fixed.