John ("John" <john@[EMAIL PROTECTED]
>) gurgled happily, sounding much like they
were saying:
> 1989 900 T
> Engine up to temperature and idling in a parking lot with the outside
> temperature around 20 degrees F. The temperature gauge starts climbing
> and at the same time the cabin heat starts blowing cold air. Once we
> start driving again the heat comes back and the temp gauge goes back to
> normal.
>
> Are we talking a bad thermostat here or am I way off base?
No, you've got the RIGHT 'stat installed.
The genuine Saab 'stat has three stages, not the usual two.
1. Block only, warm-up.
2. Full circuit, normal.
3. Rad & block only, over-temp. Heater is cut out of the loop.
First call would be to change the coolant and flush it all through -
there's a block drain under the exhaust manifold (probably seized) and
the rad drain under the RH (US passenger side) of the rad.
When you've got nice ****ny new coolant in, turn the ignition on (don't
start the car), unplug the two plugs from the rad temp switch (top LH of
rad) and short between 'em. The fans should come on. If not, that's your
problem. If they do, then start the car, and run it up to temp. If the
fans don't come on as it gets to half-scale on the temp gauge, then the
switch is at fault.
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