2004 pontiac grand prix. heating problems.?

my 2004 pontiac grand prix has heating problems. it does work, but it does stop randomly, or when you hit a bump/pot hole. we had the heater replaced and it is still doing it. could it be an electrical issue? it also didn't have this problem until last winter when a deer hit the passenger side of my car.

[melsg5]

what do you mean when you say "we had the heater replaced"? Do you mean the blower motor? If so the installer may have not fully connected the electrical plug. The other possiblity is the blower motor resistor.