Technical heater fan/blower

[jaytor]

Hey all I'm new here and last week I brought a 1.2 fiat stilo 2001/02 and have a slight problem with my heater blower, if I get in the car and leave the keys in my pocket I can turn my heater up to 4 and it will blow air out but if I start the car up the heater won't work at all but if I take the keys out the heater will work again, does anyone have a idea what could be up with this problem