<E34> Heater problems

[Hendrik Pieterse <Hendrik@xxxxxxxxxx>]

Hi

My '90 535i has a curious new problem. The two side in-dash airducts 
(just next to the speakers on top of the dash) and footwell airducts 
are constantly blowing VERY hot air, even though all others are blowing 
normal (cold) air. The only way to get cold air through them is to turn 
on the Air Conditioner or by Recirculating the air. Even then I imagine
it 
is just because the A/C air is cold enough to counter the hot air.

I have replaced the regulator and auxilary water pump (major $$$), and
the 
problem still holds. When I set the airflow to "Footwell", the car heats
up so nicely, you can boil eggs in winter! 

I suspect that it has something to do with the Heater switch in the
central 
dash airduct. I cannot see any change in behaviour when I set it to cold
versus hot. Could this be the problem? How do I get the central vents
out 
of the dash (tried without success...)
What should happen when changing the switch from cold to hot? 
Anywhere I can measure with my multimeter to determine the problem?

Fuses and such all seem fine...

Any help is much appreciated!

Hendrik

'86 323i - they don't make 'em like this no more (thank goodness!)
'90 535i - boiling hot!

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