Yes what was previously called the "sampler blower motor" could very well be the problem.

There is a small fan motor that draws air from a little vent near the dome light. It draws that air across a sensor that determines if the car is too hot or too cold. When it fails it does what you are describing.

The problem is that this little fan motor is in several different locations throughout the 124 series. You might try removing the glove box and looking and feeling to the right. This assembly is about an inch or inch and half in diameter and a few inches long. There will be a tube connected that goes off on its way to the grille near the dome light. This fan gets voltage any time the key is on.

You might try making some smoke somehow, such as a cigarette (yuck!) and when holding the smoke near the grille it should be drawn into the grille. If it doesn't draw into the grille, then it will be more important to find the motor.

Good luck,