Check the model of his car. A 924S (capital 'S' not lower case) has the early dash and thus the direct push/pull wires to the valve.
Best case is the clip that holds the sheath onto the lever arm bracket, has popped off. Worst case is the bracket ear that the clip fits over has broken off. Either way you need to remove a few things to get a look at the area.
Item 21 is the bracket.
Item 28 is the clip.
Item 27 is the cable.
Item 35 is the valve for the heater.
