Heater controls - Top Slider one

[pdu]

Problem with Heater controls on the dash - One of the 3 slider controls for the heaters (top one) gets stuck about 1/3 of the way across, sliding from left to right, any ideas please?

Also, every time I use my windscreen wiper wash I can smell the wiper fluid inside the car?

Thanks
Paul
'90 318i

[Brianmoooore]

This lever works a cable that operates a red lever that you should be able to see above the footwell heater outlet on the right hand side if you remove the panel above the driver's knees.
Usual problem is stray radio wiring caught up in the lever behind the heater panel.
Screenwash water runs off the car close to the air inlets for the heater, so there may not be anything wrong.