my car heater blower works and stops after the car is shut off it can work for a few days then stops and some times if i hit a pot hole and the heater motor would kick in and work fine then shut the car off and come back.. no blower so then i unplug the heater motor plug from the fire wall and as soon as plug it in it always goes on and the plug area its real clean no grime or corrosion could it be the plug or what eles could be causing this. it seams to happen in the colder weather summer time.. ac blows great ps thank to all who are member of this site. just did the upper intake and lower intake with help form this forum and a i had no problem car runs much better seams to be drink a little more fuel than usual but i do have some cracks in the rubber fitting air hose which might be cause the fuel to be running a little rich thanks again

Seems to me that this would be caused by a dead spot in the motor. Specially if a shock will cause to work again.

Yours are typical symptoms of a worn-out blower motor. To be certain, the next time it stops, or won't run, unplug the electrical connector at the motor and attach a 12-V test light. If the light works and the motor doesn't, it is a bad motor. A new motor is about $50. Search "blower motor" for specific instructions on R&R.