Blower motor....

Just last night I found that out the interior and defrost control works, but the heater valve is stuck open. My blower works on both low and slow speeds the fan only runs of about few seconds then quits. Looking at the blower motor plug there looks like four wires are there, I am used to the ole' two wire deal on the 74 Midget, Where should I start looking...?

I think it could be a switch problem as I have to fart around with it to get the fan going..

Follow a diagram. But if the motor is working then quits time and again, it sounds like either the motor is gone or you have a corrosion issue; wire connections or switch would fall into that. I would work that first before changing a motor.