After I changed a light bulb in my wall mounted outdoor motion dector light, it doesn't work. But it doesn't turn off or go on like it should, I even tried the test mode and the light just stays on, the unit is only about 1 yr old, it's a Hampton bay brand

Try turning breaker off, then on. If it stayes on, and no rewiring has been done, it is likely shot, many times they fail in the on condition.
There is a Maximum wattage of bulbs you can use, be careful not to exceed.