My friend has a natural gas fau. I don't know the name or age. I have not checked anything. The main burner will light and stay lit for 10-20 seconds then shut off. After about 30-60 seconds it will relight and do the same thing over and over. The blower motor never comes on. The burner is not on long enough to heat up the heater. [email protected]

There isn't enough information to really answer this one beyond saying that if the blower doesn't come on then start there. I don't even know which blower you are referring to or what else you have done or are capable of doing. It could be several things and unless you are handy at reading electrical schematics and have the correct test equipment your only recourse is to call a professional.